Answer:
1. 0.74mol
2. 0.42mol
3. 2.125mol
4. 0.301mol
5. 4.52 × 10^23 particles
Explanation:
Number of moles (n) in a substance can be found using the formula:
mole (n) = mass/molar mass
Using this formula, the following moles are calculated:
1. Molar of Na = 23g/mol
mole = 17/23
mole = 0.74mol
2. Molar mass of Na2SO4 = 23(2) + 32 + 16(4)
= 46 + 32 + 64
= 142g/mol
Mole = 60/142
mole = 0.42mol
3. Molar mass of CO2 = 12 + 16(2)
= 12 + 32
= 44g/mol
mole = 93.5/44
mole = 2.125mol
4. Molar mass of sodium nitrate (NaNO3) = 23 + 14 + 16(3)
= 23 + 14 + 48
= 85g/mol
mole = 25.6/85
mole = 0.301mol
5. Number of particles in one mole of a substance is 6.022 × 10^23 particles. Hence, in 0.75mol of calcium hydroxide (Ca(OH)2, there will be;
0.75mol × 6.02 × 10^23
= 4.515 × 10^23
= 4.52 × 10^23 particles
Someone please help i don’t have much time left
Answer: Energy of reactants = 30, Energy of products = 10
Exothermic
Activation energy for forward reaction is 10.
Explanation:
Exothermic reactions are defined as the reactions in which energy of the product is lesser than the energy of the reactants. The total energy is released in the form of heat and [tex]\Delta H[/tex] for the reaction comes out to be negative.
Energy of reactants = 30
Energy of products = 10
Thus as energy of the product < energy of the reactant, the reaction is exothermic.
Activation energy [tex](E_a)[/tex] is the extra energy that must be supplied to reactants in order to cross the energy barrier and thus convert to products.
[tex]E_a[/tex] for forward reaction is (40-30) = 10.
Hydrogen peroxide is a versatile chemical, its uses include bleaching wood pulp and fabrics and substituting for chlorine in water purification. One reason for its versatility is that it can be either an oxidizing or reducing agent. For the following reactions, identify whether hydrogen peroxide is an oxidizing or reducing agent.
a) H2O2 (aq) + 2 Fe2+ (aq) + 2 H+ + 2H20 (1) + 2 Fe3+(aq)
b) 5 H2O2 (aq) + 2 MnO4 (aq) + 6 H+ (aq) → 8 H20 (1) + 2 Mn2+ (aq) + 5 O2 (g)
Answer:
Explanation:
a )
H₂O₂ (aq) + 2 Fe²⁺ (aq) + 2 H⁺ = 2H20 (l) + 2 Fe³⁺(aq)
Here oxidation number of Fe is increasing from + 2 to + 3 so it is being oxidized . Hence H₂O₂ is acting as oxidizing agent here .
b )
5 H₂O₂ (aq) + 2 MnO₄⁻¹ (aq) + 6 H⁺ (aq) → 8 H20 (l) + 2 Mn⁺² (aq) + 5O₂ (g)
In this reaction, oxidation number of Mn is reducing from + 7 to + 2 so it is being reduced . Here H₂O₂ is acting as reducing agent .
What mass of water in grams will fill a tank 126cm long, 47 cm wide, and 13 cm high
Answer:
Mass = 76986 g
Explanation:
Given data:
Dimensions of tank = 126 cm× 47 cm× 13 cm
Mass of water required to filled = ?
Solution:
First of all we will calculate the volume of tank which is equal to the volume of water required to fill it.
Volume = length ×height ×width
Volume = 126 cm × 13 cm× 47 cm
Volume = 76986 cm³
Mass of water:
Mass = density × volume
density of water is 1 g/cm³
Mass = 1 g/cm³× 76986 cm³
Mass = 76986 g
Where would a disease transmitted by person to person contact be most likely to spread quickly
Answer: inside
Explanation:
Answer:
direct and indirect contact
Explanation:
if you touch a doorknob right after an infected person than you make be exposed to the disease.
Given the equation:
4Al2O3 + 9Fe --> 3Fe3O4 + 8Al
If 27.5 g of Al2O3 reacted with 8.4 g of Fe, how many of Fe 3O4 are formed?
a) Calculate the limiting reactant
b) Calculate the number of grams of Al produced.
c) Calculate the number of grams of Fe3O4 produced.
d) Calculate the percent yield if 10g of Fe O4 were obtained?
Answer: a) [tex]Fe[/tex] is the limiting reagent
b) 3.59 g
c) 11.6g
Explanation:
[tex]4Al_2O_3+9Fe\rightarrow 3Fe_3O_4+8Al[/tex]
To calculate the moles :
[tex]\text{Moles of} Al_2O_3=\frac{27.5g}{102g/mol}=0.27moles[/tex]
[tex]\text{Moles of} Fe=\frac{8.4g}{56g/mol}=0.15moles[/tex]
According to stoichiometry :
a) 9 moles of [tex]Fe[/tex] require= 4 moles of [tex]Al_2O_3[/tex]
Thus 0.15 moles of [tex]Fe[/tex] will require=[tex]\frac{4}{9}\times 0.15=0.067moles[/tex] of [tex]Al[/tex]
Thus [tex]Fe[/tex] is the limiting reagent as it limits the formation of product and [tex]Al[/tex] is the excess reagent.
b) As 9 moles of [tex]Fe[/tex] give = 8 moles of [tex]Al[/tex]
Thus 0.15 moles of [tex]Fe[/tex] give =[tex]\frac{8}{9}\times 0.15=0.133moles[/tex] of [tex]Al[/tex]
Mass of [tex]Al=moles\times {\text {Molar mass}}=0.133moles\times 27g/mol=3.59g[/tex]
c) As 9 moles of [tex]Fe[/tex] give = 3 moles of [tex]Fe_3O_4[/tex]
Thus 0.15 moles of [tex]Fe[/tex] give =[tex]\frac{3}{9}\times 0.15=0.05moles[/tex] of [tex]Fe_3O_4[/tex]
Mass of [tex]Fe_3O_4=moles\times {\text {Molar mass}}=0..05moles\times 231.5g/mol=11.6g[/tex]
In general, weathering tends to occur more rapidly in warm climates than in cool climates. How does this trend explain the effect of temperature on erosion rates?
Answer:
See explanation
Explanation:
Weathering refers to the breakdown of rocks to form soil. There are several agents of weathering.
In warmer regions, there are more vegetation and microorganisms and they increase the rate of biological weathering.
Since weathering leads to the formation of soil and the rate of weathering is greater in warmer climates, it also follows that as temperature increases and more soil is formed, erosion will happen faster at this higher temperature owing to the presence of more soil compared to colder climates.
There is a huge and direct effect of temperature on the rates of erosion.
The highest rate of weathering occurs in warm and wet climate because in warm and wet climatic regions, more rainfall occurs which increase the rate of weathering. Rainfall and temperature can affect the rate in which rock weathering occurs.
High temperatures and greater rainfall increase the rate of chemical weathering. Rocks in tropical regions exposed to abundant rainfall so we can conclude that hot temperatures weather much faster than similar rocks residing in cold, dry regions.
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The reactants of two chemical equations are listed.
Equation 1: AgNO3 + Zn
Equation 2: AgNO3 + MgCl2
Based on the type of reaction, which reaction can be used to extract silver metal from silver nitrate solution?
Answer: Equation 1, because Zn being more reactive, replaces Ag from AgNO3
Explanation: I got it right on the quiz and it replaces it
Cleavage refers to the way a rock:
A. shine
B. breaks
C. streaks
D. is made
Explanation:
Türküm ben yanlisikla siteye girdim.
Answer:
breaks
Explanation:
I think its braks
Benzophenone has a normal freezing point of +48.1 oC, with freezing point depression constant Kfpt = − 9.78 oC/m. A 0.1500 molal solution of ionizing salt had a freezing point of +44.0 oC. What is the van't Hoff (ion dissociation) constant i for this salt? (i.e., the average number of ions produced in the solution.) Report 3 significant digits.
Answer:
i = 2.79
Explanation:
The excersise talks about the colligative property, freezing point depression.
Formula to calculate the freezing point of a solution is:
Freezing point of pure solvent - Freezing point of solution = m . Kf . i
Let's replace data given. (i = Van't Hoff factor, numbers of ions dissolved in solution)
48.1°C - 44°C = 0.15 m . 9.78°C/m . i
4.1°C / (0.15 m . 9.78°C/m) = i
i = 2.79
In this case, numbers of ions dissolved can decrease the freezing point of a solution, which is always lower than pure solvent.
Please help me on this
You want to compare the malleability of
two metals. Plan an investigation that would allow you to determine
which metal is more malleable .
The temperature and the strength of the metallic link are the two most crucial variables that can impact how malleable a metal or alloy is.
What is metal ?A metal is a substance that has a shiny look when freshly processed, polished, or shattered, and conducts electricity and heat rather effectively. Generally speaking, metals are malleable and ductile.
The amount of pressure that a metal can sustain without breaking can be used to gauge its malleability. Varied metals have different degrees of malleability because of variations in their crystal structures.
The temperature of the metal and the strength of the metallic connection are the two parameters that define how malleable a metal or metal alloy will be.
Thus, The kind of the metallic connection can have a significant impact on how easily metal atoms can rearrange themselves.
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ASAP I WILL GIVE BRAINLIEST The diagram shows a lever. What is the mechanical advantage of the lever? O 2 03 3 m 6 m mi 0 9
Answer:
A) 2
Explanation:
Answer:
2, i got it right thanks to the other user :) <3
Explanation:
Which statement defines the enthalpy of solution?
the total number of particles in a solution
the phase change from a solid to a liquid
o the difference in characteristics between reactants and products
the change in energy when one substance dissolves in another
Answer:
the change in energy when one substance dissolves in another
Explanation:
The enthalpy changes are the heat changes accompanying physical and chemical changes. Actually, an enthalpy change is the difference between the sum of the heat contents of products (final state) and sum of the heat contents of reactants (initial state).
There are basically two types of heat changes that accompanies are reaction which are:
Exothermic changes Endothermic changesTherefore, the change in energy when one substance dissolves in another defines the enthalpy of solution.
Enthalpy of solution is the heat liberated or absorbed when one mole of a substance (solute) is dissolved in a specified volume of solvent (water).
Identify the true statements about surface tension. Molecules along the surface of a liquid behave differently than those in the bulk liquid. Water forming a droplet as it falls from a faucet is a primary example of surface tension. Surface tension increases as the temperature of the liquid rises. Cohesive forces attract the molecules of the liquid to one another. Mercury has a lower surface tension than water.
Answer:
Molecules along the surface of a liquid behave differently than those in the bulk liquid.
Cohesive forces attract the molecules of the liquid to one another.
Water forming a droplet as it falls from a faucet is a primary example of surface tension.
Explanation:
Surface tension is the force that stretches the liquid surface. This force acts normal to the surface. It is the downward force that acts on the surface of the liquids which is due to the cohesive forces of the liquids.
The water molecules are bonded by a strong hydrogen bond force which is between hydrogen atom and the electronegative oxygen atom. At the surface the water molecules are attracted strongly by other water molecules which lies below the surface and are stretched at the surface. Thus the water molecules at the surface acts differently than in the bulk liquid.
Mercury have a strong cohesive force than the water and have a higher surface tension force than the water.
Surface water acquires minimum surface area, hence acquiring spherical shape of water.
What is the atomic number?
pls help.
Answer:
8
Explanation:
Which refers to any disturbance that carries energy from one place to another? wave trough motion crest
Answer:
Wave
Explanation:
Wave refers to any disturbance that carries energy from one place to another.
What is wave?Wave refers to disturbance or variation that occur in a body travelling or in motion which travels from one medium to another by transmitting energy from one location which is the origin to another location without transporting matter.
Therefore, Wave refers to any disturbance that carries energy from one place to another
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The concentration of lithium chlorite solution is 12.0% by mass. In a ___g sample of this solution, there are 238.5g of dissolved lithium chlorate.
Answer is A) 1990 but I do not know to go to there please help!
Mass of sample : 1987.5 g≈1990 g
Further explanationGiven
12% mass of Lithium chlorate
Required
Mass of sample
Solution
%mass = (mass of solute/mass of solution) x 100%
mass of solute = mass of Lithium chlorate = 238.5 g
Input the value :
12/100(0.12) = 238.5 g : mass of solution
mass of solution =238.5 : 0.12
mass of solution = 1987.5≈1990 g
What is another name for infrared energy? Choose all that apply.
Question 1 options:
Microwave energy
Visible light
Thermal energy
Heat
Answer: not 100% but maybe Visable Light...sorry if thats wrong
Explanation:
Thermal energy is the another name for infrared energy.
What is infrared radiation?Infrared radiation is a type of radiant energy that is not visible to human eyes but we can feel as heat energy.
Infrared radiation (IR), also known as thermal radiation. It is that band of energy in the electromagnetic radiation spectrum with wavelengths between 780 nm and 1 mm so we can conclude that thermal energy is the another name for infrared energy.
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Consider the following chemical equilibrium:
NH4SH(s) ⇌ H2SgNH3(g) Now write an equation below that shows how to calculate Kp from Kc for this reaction at an absolute temperature T. You can assume T is comfortably above room temperature. If you include any common physical constants in your equation be sure you use their standard symbols, found in the ALEKS Calculator.
Answer:
See explanation below
Explanation:
First, let's write the reaction:
NH₄SH(s) <------> H₂S(g) + NH₃(g)
The reaction is already balanced so we don't need to do anything else.
Second, let's take into account the following. The Kc expression for this reaction, only compounds in gaseous state are the only ones that contribute to the equilibrium. Solid and liquid do not contribute to the Kc expression. This is because solid and liquid have a constant concentration near to 1, so, it won't do any difference.
Knowing this, the Kc expression for this reaction is:
Kc = [H₂S] [NH₃]
Now, to calculate Kp from Kc, there's an expression that helps a lot to do this. The expression is the following:
Kp = Kc (RT)ᵃⁿ (1)
Where:
R: universal constant of gases
T: Temperature in K
ᵃⁿ = difference of the coefficients of the reaction.
This expression comes from the fact that Kp is an expression that instead of working with concentrations, it works with pressure.
If we use the ideal gas equation we have:
PV = nRT
Solving for P:
P = nRT/V and C = n/V so
P = CRT
If we now replace this, in the Kp expression of equilibrium we have:
Kp = pH₂S * pNH₃
Kp = ([H₂S]RT)¹ ([NH₃]RT)¹
Kp = (RT)¹⁺¹ ([H₂S] [NH₃])
Kp = (RT)²Kc
So finally the expression for Kp would be:
Kp = Kc (RT)²Hope this helps
An average reaction rate is calculated as the change in the concentration of reactants or products over a period of time in the course of the reaction. An instantaneous reaction rate is the rate at a particular moment in the reaction and is usually determined graphically, but it can also be calculated using calculus. The reaction of compound A forming compound B was studied and the following data were collected:
Time (s) [A] (M)
0. 0.184
200. 0.129
500. 0.069
800. 0.031
1200. 0.019
1500. 0.016
Required:
a. What is the average reaction rate between 0 and 1500s?
b. What is the average reaction rate between 200. and 1200s ?
c. What is the instantaneous rate of the reaction at t=800s?
Answer:
Explanation:
a )
Average reaction rate between 0 and 1500s
Time duration = 1500 s
moles reacted = .184 - .016 = .168 moles
Moles reacted per second = .168 / 1500
= 112 x 10⁻⁶ moles /s
b )
Average reaction rate between 200 and 1200s
Time duration = 1000 s
moles reacted = .129 - .019 = .11 moles
Moles reacted per second = .11 / 1000
= 110 x 10⁻⁶ moles /s
c )
the instantaneous rate of the reaction at t=800s
We shall assume that between 500 s and 1200 s , rate of reaction is uniform
rate between 500 and 1200
Time duration = 700 s
moles consumed = .069 - .019 = .05 moles
Rate of reaction = .05 / 700
= 71 .4 x 10⁻⁶ moles / s
This will also be instantaneous rate of reaction at t = 800 s .
A sample of PCl5 weighting 2.69 gram was placed in 1.00 Litter container and completely vaporized at 250C. The pressure observed at that temperature was 1.00 atm. The possibility exists that some of the PCl5 dissociated according to PCl5 (g) ! PCl3 (g) Cl2 (g) . What must be the partial pressures of PCl5 PCl3 and Cl2 under these experimental conditions
Answer:
Partial pressures:
PCl₅ = 0.558 atm
PCl₃ = 0.22 atm
Cl₂ = 0.22 atm
Explanation:
From the given information:
The number of moles of PCl₅ associated with the evaporation is:
[tex]n_{PCl_5}= \dfrac {weight \ of \ PCl_5} {M.Wt. \ of \ PCl_5}[/tex]
[tex]n_{PCl_5}= \dfrac {2.69 \ g} {208.5 \ g/mol}[/tex]
[tex]n_{PCl_5}= 0.013 \ mol[/tex]
Temperature of the gas = 250° C = (250 + 273.15) K
= 523.15 K
Using the Ideal gas equation to determine the pressure exerted by the completely vaporized PCl₅
PV = nRT
[tex]P = \dfrac{nRT}{V}[/tex]
[tex]P = \dfrac{0.0013 \ mol \times 0.082 \ Latm^0 K^{-1} . mol ^{-1} \times 523.15 \ K}{1.0 \ L}[/tex]
P = 0.558 atm
Thus, at 250° C, decomposition of PCl₅ occurs.
In the container, PCl₅ decomposes to PCl₃ and Cl₂.
i.e.
[tex]PCl_{5(g)} \to PCl_{3(g)}+ Cl_{2(g)}[/tex]
Using Dalton's Law:
[tex]P_{total } =P_1 + P_2+P_3 +...[/tex]
[tex]P_1 = P_{Total} \times X_1[/tex]
where;
X = mole fraction
Then, the total no. of moles in the container is:
[tex]n = \dfrac{PV} {RT}[/tex]
[tex]n = \dfrac{1\ atm \times 1.0\ L}{0.0821 \ L \ atm \ K^{-1}.mol \times 523.15\ K}[/tex]
n = 0.023 mol
Now, the container contains a total amount of 0.023 mol where initially 0.013 mol are that of PCl₅ and remaining 0.005 mol of PCl₃ and 0.005 mol of Cl₂.
Thus, the partial pressure of PCl₃ is:
[tex]P__{PCL_3} }= P_{total} \times \dfrac{no. \ of \ moles \ of PCl_5}{total \ no. \ of \ moles}[/tex]
[tex]P__{PCL_3}} = 1 \ atm \times \dfrac{0.005}{0.023}[/tex]
[tex]P__{PCL_3}} = 0.22 \ atm[/tex]
Thus, since the no of moles of PCl₃ and Cl₂ are the same, then the partial pressure for Cl₂ is = 0.22 atm
How many orbitals in an atom can have each of the following designations:
(a) 1s;
(b) 4d;
(c) 3p;
(d) n=3?
Answer:
(a) 1s; has one orbital
(b) 4d; has five orbitals
(c) 3p; has three orbitals
(d) n=3 has nine orbitals
Explanation:
Electrons in an atom are always in constant motion, making it hard to predict there exact position. However, the most probable locations electrons can be be found are described with the terms shells, subshells and orbitals. A shell contains subshells and orbitals are found within subshells. The shells are given names such as K, L, M, N, which correspond to the principal quantum numbers, n = 1, 2, 3, and 4 respectively. There are 4 major types of subshells that can be found in a shell. They are named as s, p, d, f. Each subshell is composed of several orbitals.
a. 1s; the s subshell has only one orbital. Therefore, the 1s subshell has one orbital
b. 4d; the d subshell has five orbitals. Therefore, the 4d subshell has five orbitals
c. 3p; the p subshell has three orbitals. Therefore, the 3d subshell has three orbitals
d. n = 3; the shell with n = 3 has the following subshells, 3s, 3p, 3d.the number of orbitals will be 1 + 3 + 5 = 9 orbitals. Therefore, the number of orbitals in n = 3 is nine orbitals
Allows ingestion and breaks down food so that nutrients can be absorbed???
Answer:
Salivation allows the ingestion of food while digestive juices aids breakdown of food and absorption of nutrients.
Explanation:
When food is taken into the mouth, the presence of food triggers a nervous reflex that causes the salivary gland to produce saliva in the mouth. Once the food particles have been ingested the digestive system breaks down the food into smaller components with the aid of the digestive juices.
identify the equipment best suited for extinguishing each type of fire. Your choices are: fire extinguisher, overturned beaker, fire blanket.
Answer: The equipment best suited for extinguishing each type of fire are listed below:
--> Fire extinguisher: Large fire on the floor
--> Overturned beaker: Small benchtop fire
--> Fire blanket: clothing fire.
Explanation:
Fire outbreaks is a common event that can be prevented in a standard chemistry laboratory with the aid of fire safety equipments.
The method used by these equipments to extinguish fire is to suffocate the fire by obstructing the source of oxygen, by reducing the heat with the use of water and removing the fuel or oxygen source.
These fire safety equipments should be highly visible and easily accessible in a laboratory. Example of fire safety equipments includes:
--> Fire extinguisher: A laboratory personnel needs to be trained in the use of this since it's made up of different types. it can be used to extinguish ( put out) large fire on the floor.
--> Overturned beaker: this can be used to suffocate small fire on the bench which is also common in the laboratory.
-->Fire blanket: This should be used in the event that a person’s body or clothing catches fire.
table salt conducts electricity in water, but sugar does not. Explain why?
Answer:
Because sugar has no ions in the solution
Explanation:
Pure water contains very few ions, so it does not conduct electricity very well. When table salt is dissolved in water, the solution conducts very well, because the solution contains ions. When sugar is dissolved in water, the solution does not conduct electricity, because there are no ions in the solution.
In basic words the more ions in the solution there is a better chance to conduct electricity.
Which pair of elements would you expect to exhibit the greatest similarity in their physical
and chemical properties?
Select one:
O a. No
O b. Mg, Al
O c. Br, Kr
O d. As, Br
O e. I, AT
Answer:
e. I, At
Explanation:
Hello!
In this case, since the periodic trends of a series of elements belonging to the same group towards physical and chemical properties tend to be the same when closer in period, we notice that Mg and Al, Br and Kr and As and Br are close but in period, not in the same group; therefore e. I, At, iodine and astatine, are going to tend to exhibit the greatest similarity in their physical and chemical properties.
Best regards!
A reaction between liquid reactants takes place at in a sealed, evacuated vessel with a measured volume of . Measurements show that the reaction produced of sulfur hexafluoride gas. Calculate the pressure of sulfur hexafluoride gas in the reaction vessel after the reaction. You may ignore the volume of the liquid reactants. Round your answer to significant digits.
Answer:
0.41 atm
Explanation:
A reaction between liquid reactants takes place at 10.0 °C in a sealed, evacuated vessel with a measured volume of 5.0 L. Measurements show that the reaction produced 13. g of sulfur hexafluoride gas. Calculate the pressure of sulfur hexafluoride gas in the reaction vessel after the reaction. You may ignore the volume of the liquid reactants. Round your answer to 2 significant digits.
Step 1: Given data
Temperature (T): 10.0 °CVolume of the vessel (V): 5.0 LMass of sulfur hexafluoride gas (m): 13. gStep 2: Convert "T" to Kelvin
We will use the following expression.
K = °C + 273.15
K = 10.0 °C + 273.15 = 283.2 K
Step 3: Calculate the moles (n) of SF₆
The molar mass of SF₆ is 146.06 g/mol.
13. g × 1 mol/146.06 g = 0.089 mol
Step 4: Calculate the pressure (P) of SF₆
We will use the ideal gas equation.
P × V = n × R × T
P = n × R × T/V
P = 0.089 mol × (0.0821 atm.L/mol.K) × 283.2 K/5.0 L = 0.41 atm
A student prepared several aqueous sodium chloride (NaCl) solutions to observe boiling point elevation at various molal concentrations, however, several errors were made throughout the procedure. Determine whether these errors would cause the observed boiling point to be increased or decreased relative to the expected boiling point, based on the procedure, or have no effect on the experimental results.
The question is incomplete, the complete question is;
A student prepared several aqueous sodium chloride (NaCl) solutions to observe boiling point elevation at various molal concentrations, however, several errors were made throughout the procedure. Determine whether these errors would cause the observed boiling point to be increased or decreased relative to the expected boiling point, based on the procedure, or have no effect on the experimental results.
* The flask is washed with water but not thoroughly dried before preparing the solution
* The mass of NaCl used to prepare the solution is 5.400 grams instead of 4.400 grams
* Some of the prepared solution splashes out of the flask prior to observation of the boiling point
* When making the salt solution, 55.0 milliliters of water is added instead of 50.0 milliliters
Answer:
The flask is washed with water but not thoroughly dried before preparing the solution - decrease
The mass of NaCl used to prepare the solution is 5.400 grams instead of 4.400 grams
-increase
Some of the prepared solution splashes out of the flask prior to observation of the boiling point- have no effect
When making the salt solution, 55.0 milliliters of water is added instead of 50.0 milliliters- decrease
Explanation:
If the flask is washed but not dried, then the solution will be further diluted than expected. As a result of this further dilution, the observed boiling point will be less than the expected boiling point because the boiling point depends on the solution's concentration.
If more solute is added than expected, the concentration of the solution is increased and the boiling point also increases above the expected boiling point due to the increase in amount of solute present.
If some of the solution splashes out of the flask prior to boiling, the boiling point is not affected because the concentration of the solution was not altered. The boiling point only changes when the concentration of the solution is changed.
If 55 ml of water is added instead of 50 ml, the solution is now more dilute than expected thereby reducing the concentration of the solution and the boiling point. Remember that, as the concentration of the solution decreases, the boiling point decreases accordingly.
The number of atoms in 10. grams of calcium is equal to 6.0 x 1023 multiplied by which number?
Answer:
1.51×10²³ atoms.
Explanation:
From the question given above, the following data were obtained:
Mass of Calcium (Ca = 10 g
Number of atom of Calcium (Ca) =?
The number of atoms present in 10 g of Ca be obtained as follow:
From Avogadro's hypothesis, we understood that 1 mole of any substance contains 6.02×10²³ atoms. This implies that 1 mole Ca contains 6.02×10²³ atoms.
1 mole of Ca = 40 g.
Now, if 40 g of Ca contains 6.02×10²³ atoms.
Therefore, 10 g of Ca will contain = (10 × 6.02×10²³) / 40 = 1.51×10²³ atoms.
Thus, 10 g of calcium contains 1.51×10²³ atoms.
Given:
BO3 + 3Mg → 3MgO + B
1. How many moles of Mg are required if 2 moles of B are produced?
Answer:
6moles of Mg
Explanation:
The reaction expression is given as:
BO₃ + 3Mg → 3MgO + B
Given:
Number of moles of B produced = 2 moles
Unknown:
Number of moles of Mg required = ?
Solution:
From the balanced reaction expression:
1 mole of B is produced from 3 moles of Mg
2 moles of B will be produced from 2 x 3 = 6moles of Mg