Dale is speaking to a group of students about the importance of extracurricular activities. He provides specific scenarios to show the audience how the information presented will affected them directly. Dale is fulfilling which goal of informational speaking?
to enhance understanding
to be heard
to maintain interest
to be remembered
compare and contrast synthesis reactions and decomposition reaction
Answer:
See explanation
Explanation:
Synthesis reaction and decomposition reactions are two opposing processes.
While a synthesis reaction has to do with the formation of a substance from its constituents, decomposition deals with the breakdown of a substance into its constituents.
While decomposition requires energy and is an endothermic process, synthesis is usually an exothermic process in which energy is given off as stable products are formed.
In a space shuttle, the Carbon dioxide, CO2 that the crew exhales is removed from the air by a reaction within canisters of Lithium Hydroxide, LiOH. The LiOH is only 85% efficient. On average, each astronaut exhales around 20.0 mol of CO2 every day. What volume of water is produced when the CO2 reacts with the excess LiOH
Answer:
What volume of water is produced when the CO2 reacts with the excess LiOH
X = 360 mL H2O
Explanation:
CO2 (g) + 2 LiOH(s) ⇒ Li2CO3 (aq) + H2O(l)
20.0 mol excess x g
X = 360 mL H2O
x mL H20 = 20.0 mol CO2 (1 mol H2O /1 mol CO2)(18 g H2O/1 mol H2O)
(1 mL H2O /1 g H2O)
X = 360 mL H2O
A 1.018 g sample pure platinum metal was reacted with HCl to form 1.778 g of a compound containing only platinum and chlorine. What is the percent by mass of platinum?
Answer:
57.26 %
Explanation:
Step 1: Write the balanced equation
Pt + 2 HCl ⇒ PtCl₂ + H₂
Step 2: Calculate the mass of Pt in 1.778 g of PtCl₂
According to the law of conservation of the mass, all the mass of Pt in the reactants must be present in the products. Since PtCl₂ is the only product that contains Pt, the mass of Pt is 1.018 g
Step 3: Calculate the percent by mass of platinum in PtCl₂
We will use the following expression.
%Pt = mPt / mPtCl₂ × 100%
%Pt = 1.018 g / 1.778 g × 100% = 57.26 %
Created when one substance is dissolved into another substance ? Is that a suspension. Solution or pure substance
Answer:
cemical change
Explanation:
Answer: A Solution
Explanation: A solution is made when a substance like salt is poured into water. The result would be a solution. Salt being a solid and water being a liquid.
A change of state is a(n)
process.
A. irreversible
B. reversible
Answer:
Changes of states are reversible, you can go from a solid to liquid and liquid to solid.Answer:
Reversible
Explanation:
Changes of state are physical changes in matter. Common changes of the state include melting, freezing, sublimation, deposition, condensation, and vaporization.
When measuring the volume of a liquid, how would sample size (e.g., using a 10 mL graduated cylinder vs. a 100 mL graduated cylinder to measure out 70 mL of a liquid) affect the absolute error and percentage error in the measured values of mass and volume and therefore the density
Answer:
Explanation:
From the given information:
The accuracy depends on the internal diameter of the cylinder. The cylinder with the least internal diameter is obviously more precise.
Let's assume 1% is the error of measurement.
Then, to measure 70 mL from 10 mL cylinder
The error = [tex]10 \times \dfrac{1}{100} \times 7[/tex]
= 0.7 mL
However; for a 100 mL cylinder, the error = 1 mL
Now,
The total volume for 10 mL = (70 + 0.7) = 70.7 mL
The total volume for 100 mL = (70 + 1 ) = 71 mL
Suppose the density (d) is same for both
Then;
the mass of 10 mL = ( d × 70.7) g
the mass pf 100 mL = (d × 71) g
Thus, the mass of 100 mL is greater than that of 10 mL.
Answer the given question: use Chapter 1 of notebook
How many formula units are there in 3.20x 102 moles of LICI? (2pts.)
Conversion factor: 1 mole LICI=
_formula of LICI
Students, draw anywhere on this slide!
Answer:
1.93 x 10²⁶ formula units
Explanation:
Given parameters:
Number of moles of LiCl = 3.2 x 10² moles = 320moles
Unknown:
Number of formula units in this compound = ?
Solution:
The mole is used a reference to determine the number of substances matters contain.
A mole contains the Avogadro's number of particles.
So;
1 mole of a substance contains 6.02 x 10²³ formula units;
320 moles of LiCl will contain 320 x 6.02 x 10²³ = 1.93 x 10²⁶ formula units
us
If the mole fraction of NaCl in an
aqueous solution is 0.0927, what is
the weight/weight % (percent by
mass) of NaCl.
Molar Mass
Naci: 58.44 g/mol
H2O: 18.016 g/mol
Answer:
24.9%
Explanation:
According to this question, mole fraction of NaCl in an aqueous solution is 0.0927. This means that the mole percent of NaCl in the solution is:
0.0927 × 100 = 9.27%
Let's assume that the solution contains water (solvent) + NaCl (solute), hence, the mole fraction of water will be;
100% - 9.27% = 90.73%
THEREFORE, it can be said that, NaCl contains 0.0927moles while H2O contains 9.073moles
N.B: mole = mass/molar mass
Given the Molar Mass
NaCl: 58.44 g/mol
H2O: 18.016 g/mol
For NaCl;
0.0927 = mass/58.44
mass = 0.0927 × 58.44
5.42g
For H2O;
9.073 = mass/18.016
mass = 9.073 × 18.016
= 16.35g
Total mass of solution = 16.35g + 5.42g = 21.77g
Mass percent of NaCl = mass of NaCl/total mass × 100
% mass of NaCl = 5.42g/21.77g × 100
= 0.249 × 100
= 24.9%
Answer:
24.9
Explanation:
YOU MUST SHOW YOUR WORK FOR FULL CREDIT!
1. Jimmy picks up a 5kg box and places it on a shelf 1 meter from the ground. What is the
gravitational potential energy of the box?
Answer: 49 joules
Explanation: gravitational potential energy = mgh
m= mass kg, g= acceleration due to gravity 9.8 m/sec/sec, h= height m
=5*9.8.1 joules = 49 joules
help now plsss I really need help !!!!
Answer:
4
Explanation:
the one you ARE ON
What is the difference between the grassland and savanna biomes?
A)Grassland biomes are closer to the equator and receive more rain.
B)Savanna biomes are closer to the equator and receive more rain.
C)Grassland biomes contain mostly grasses.
D)Savanna biomes contain mostly grasses.
Answer:
C)Grassland biomes contain mostly grasses.
Explanation:
The main differences between a savanna biome and a grassland is that grasslands biomes contain mostly grasses.
Savanna are made up of both grasses and shrubs.
Savanna are a mix of grasslands with some scattered trees in the area. Grasslands are open grass fields. They do not contain much trees as such. The savanna and grasslands are renowned for their fauna diversity of beasts.Define degree of hardness of water? Mention different units.
Answer:
Degree of hardness is defined as the number of parts of calcium carbonate or equivalent to various calcium and magnesium salts present in a million parts of water by mass.
Explanation:
General guidelines for classification of waters are: 0 to 60 mg/L (milligrams per liter) as calcium carbonate is classified as soft; 61 to 120 mg/L as moderately hard; 121 to 180 mg/L as hard; and more than 180 mg/L as very hard. Lime scale buildup inside a water pipe
Units: mg/l , ppm , kg/[tex]m^{3}[/tex] , ppb , g/L
Write a description of how you know a chemical reaction is occurring.
ANSWER FAST FIRST PERSON GETS BRAINLIEST
Answer:
See explanation
Explanation:
Chemical reactions are also referred to as chemical change. A chemical change often leads to the formation of new substances and is not easily reversible.
A chemical reaction may be accompanied by the emission of heat and light, formation of a precipitate, evolution of gas, or a color change.
These observable physical effects may tell us weather a chemical reaction has taken place or not so we have to observe the system closely for any of these effects stated above.
How was Bohr's atomic model different from those of previous scientists?
Answer:
Bohr placed the electrons in distinct energy levels. Rutherford described the atom as consisting of a tiny positive mass surrounded by a cloud of negative electrons. Bohr thought that electrons orbited the nucleus in quantized orbits. Also, rutherfords was just a hypothesis while Bhor took the time to make his an experiment
Classify each of the following compounds as a strong acid, weak acid, strong base, or weak base, and write the Ka expression for any weak acid or weak base:
1. [ Select ] ["strong base", "weak base", "strong acid", "weak acid"] LiOH
2. [ Select ] ["weak acid", "strong acid", "strong base", "weak base"] HF
3. [ Select ] ["strong acid", "weak acid", "strong base", "weak base"] HCl
4. [ Select ] ["weak base", "strong base", "weak acid", "strong acid"] NH3
Ka expression: [ Select ] ["[H+][F-] / [HF]", "[Li+][OH-]/ [LiOH]", "[H+][Cl-} / [HCl]", "[NH4+] / [NH3]", "[HF] / [H+][F-}", "[LiOH] / [Li+][OH-]", "[HCl] / [H+][Cl-}", "none"]
Calculate the concentration of OHLaTeX: -? in a solution that has a concentration of H+ = 7 x 10LaTeX: -?6 M at 25°C. Multiply the answer you get by 1010 and enter that into the field to 2 decimal places.
Answer:
See explanation below
Explanation:
There are several ways to know if an acid or base is strong. One method is calculating the pH. If the pH is really low, is a strong acid, and if it's really high is a strong base.
However we do not have a pH value here.
The other method is using bronsted - lowry theory. If an acid is strong, then his conjugate base is weak. Same thing with the bases.
Now, Looking at the 4 compounds, we can say that only two of them is weak and the other two are strong compounds. Let's see:
LiOH ---> Strong. If you try to dissociate :
LiOH ------> Li⁺ + OH⁻ The Li⁺ is a weak conjugate acid.
HF -----> Weak
HF --------> H⁺ + F⁻ The Fluorine is a relatively strong conjugate base.
HCl -----> Strong
This is actually one of the strongest acid.
NH₃ ------> Weak
Now writting the Ka and Kb expressions:
Ka = [H⁺] [F⁻] / [HF]
Kb = [NH₄⁺] [OH⁻] / [NH₃]
Finally, to calculate the [OH⁻] we need to use the following expression:
Kw = [H⁻] [OH⁻]
Solving for [OH⁻] we have:
[OH⁻] = Kw / [H⁺]
Remember that the value of Kw is 1x10⁻¹⁴. So replacing:
[OH⁻] = 1x10⁻¹⁴ / 7x10⁻⁶
[OH⁻] = 1.43x10⁻⁹ M
And now, multiplying by 10¹⁰ we have:
[OH⁻] = 1.429x10⁻⁹ * 1x10¹⁰
[OH⁻] = 14.29Hope this helps
Strong acids and bases are those which completely ionized in body fluid, and weak acids and bases are those who does not completely ionized in body fluid.
Ka expression is used to differentiate between strong and weak acids.
Which are strong acids and base and weak acids and bases?LiOH - strong baseHF - weak acidHCl - strong acidNH3 - weak baseWhat are the Ka expression of the following?Weak acid – HF[tex]\bold{\dfrac{[H+][F-]}{[HF]}}[/tex]
Weak base – NH3[tex]\bold{\dfrac{[NH_4^+] [OH^-]}{[NH_3]} }[/tex]
Calculate the concentration of OH?Given, [tex]\bold{ [H^+]=1\times10^-^6\; at \;25^oC}[/tex]
We know, [tex]\bold{ [H^+]\times[OH^-]=1\times10^-^6\; at \;25^oC}[/tex]
[tex]\bold{[OH^-]=\dfrac{1\times10^-^1^4}{6.2\times10^-^6} = 1.43\times10^-^9}[/tex]
Now, multiplying the value by [tex]10^1^0[/tex]
[tex]\bold{( 1.429\times10^-^9) \times 1\times10^1^0= 14.29}[/tex]
Thus, the value is 14.29.
Learn more about acid and base, here:
https://brainly.com/question/10468518
which type of bond involves 2 different metals?
A. ionic
B. Covalent
C.Metallic
D. Bonding would not occur
Answer:
iconic bond is the answer
I hope it helps you ✌
Name the intermolecular force that corresponds to: an attraction between a partially positive region in one molecule and a partially negative region in another molecule. an attraction between two temporarily polarized molecules. an attraction between a negatively charged particle and a partially positive region in a molecule. an attraction between a partially positive hydrogen atom in a molecule and a partially negative and highly electronegative atom on another molecule.
Answer:
an attraction between a partially positive region in one molecule and a partially negative region in another molecule....dipole-dipole interaction
an attraction between two temporarily polarized molecules...dispersion forces
an attraction between a negatively charged particle and a partially positive region in a molecule....ion dipole interaction
an attraction between a partially positive hydrogen atom in a molecule and a partially negative and highly electronegative atom on another molecule....Hydrogen bonding
Explanation:
Some molecules have permanent dipole. As a result of this, the positive part of one molecule may attract the negative part of the other molecule leading to dipole-dipole interaction.
Dispersion forces occur in all molecules and is as a result of temporary polarization of a molecule due to instantaneous dipole–induced dipole attractions.
If a charged particle is attracted by a dipole in a molecule, we call it ion-dipole interaction.
When hydrogen is bonded to a highly electronegative element, the positive end of the dipole is on hydrogen while the negative end of the dipole is on the electronegative element. Molecular associations often result from this permanent dipole and is called hydrogen bonding, e.g, HF.
what is the correct name of Fe(CN)3?
Answer:
Iron(III) Cyanide
Riboflavin is one of the B vitamins It is also known as B6 and is made up of carbon, hydrogen, nitrogen and oxygen atoms. When 10.0 g of vitamin B6 is burned in oxygen, 19.88 g of CO2 and 4.79 g of H2O are obtained. Another experiment shows that vitamin B6 is made up of 14.89% of N. What is the simplest formula for vitamin B6
Answer:
C₁₇H₂₀N₄O₆
Explanation:
First, we need to determine the percentage of the atoms in the molecule. Then, assuming a basis of 100 we must convert the mass of each atom to moles. Simplest formula is the simplest ratio of atoms presents in the molecule:
%C:
19.88g CO2 * (12.01g/mol C / 44.01g/mol CO2) = 5.425g C
5.425g C / 10.0g * 100 = 54.25% C
%H:
4.79g H2O * (2*1.01g/mol / 18.015g/mol) = 0.537g H
0.537g H / 10.0g * 100 = 5.37%
%N:
14.89%
%O:
100 - 14.89% - 54.25% - 5.37% = 25.49%
Moles of each atom in a basis of 100g:
C: 54.25g * (1mol / 12.01g) = 4.517moles
H: 5.37g * (1mol / 1.01g) = 5.317 moles
N: 14.89g * (1mol / 14.01g) = 1.063 moles
O: 25.49g * (1mol / 16g) = 1.593 moles
Dividing each amount of moles in the lower number of moles (moles N):
C = 4.517mol / 1.063mol = 4.25
H = 5.317mol / 1.063mol = 5
N = 1.063mol / 1.063mol = 1
O = 1.593mol / 1.063mol = 1.5
This ratio multiplied 4 times to obtain whole-numbers:
C = 4.25*4 = 17
H = 5*4 = 20
N = 1*4 = 4
O = 1.5*4 = 6
The simplest formula for vitamin B6 is:
C₁₇H₂₀N₄O₆Which of these has the most kinetic energy?
A. a 25 kg fish tank sitting on a table
B. a .05 g fish swimming in a fish tank
C. a 7,500 kg car parked on a steep hill
D. a 50 kg boulder suspended from a cliff
What is the function of the chloroplast? A. Breaks down sugar to make energy B. To hold the cell together C. To make animals green D. Uses sunlight to create glucose (sugar)
Answer:
D. Uses sunlight to create glucose (sugar)
Explanation:
The function of the chloroplast is that it uses sunlight to create glucose.
The chloroplast allows for light to be trapped which is used for the synthesis of glucose from carbon dioxide and water.
The chloroplast is a rich in a pigment called the chlorophyll. This chlorophyll is a green pigment which allows for the trapping of solar energy
This solar energy is used to carryout the photosynthetic reaction.
What volume, in liters, would 88.9 grams of a substance occupy if it’s density is 2.38 g/mL
Answer:
V = 0.03735 mL
Explanation:
Given that,
Mass of a substance, m = 88.9 grams
Density of a substance, d = 2.38 g/mL
We need to find the volume occupied by the object. The density of an object is given by mass per unit volume.
[tex]d=\dfrac{m}{V}\\\\V=\dfrac{m}{d}\\\\V=\dfrac{88.9}{2.38}\\\\V=37.35\ mL\\\\V=0.03735\ L[/tex]
So, the volume of the substance is 0.03735 mL.
7. You are about to perform some intricate electrical studies on single skeletal muscle fibers from a gastronemius muscle. But first, you must prepare 6L of a 170 mM NaCl solution in which to bath the isolated muscle during your studies. How many grams of NaCl must you weigh out on the lab balance to prepare this bath solution
Answer:
58.61 grams
Explanation:
Taking The molecular weight of NaCl = 58.44 grams/mole
Determine how many grams of NaCl to prepare the bath solution
first we will calculate the moles of NaCl that is contained in 6L of 170 mM of NaCI solution
= ( 6 * 170 ) / 1000
= 1020 / 1000 = 1.020 moles
next
determine how many grams of NaCl
= moles of NaCl * molar mass of NaCl
= 1.020 * 58.44
= 58.61 grams
what state of matter travels in straight lines
Answer:
light
Explanation:
light is plasma, which is a state of matter
HELLOSOEOODORODODODORRLKRKLRLRLF
Answer:
I'd say maybe Dangerous? I hope this helps
Answer:
golden is sometimes referred to as shiny and beatitful
Explanation:
A brown dye has a percent composition of 62.41% C, 5.24% H, and 32.36% N by mass with a molar mass of 346.40 g/mol. Determine the molecular formula of the dye
The molecular formula : C₁₈H₁₈N₈
Further explanationGiven
62.41% C, 5.24% H, and 32.36% N
Required
The molecular formula
Solution
mol ratio
C : 62.41/12.0096 = 5.1967
H : 5.24/1.00784 = 5.1992
N : 32.36/14.0067 = 2.310
Divide by 2.310(smallest)
C : 5.1967/2.31=2.25
H : 5.1992/2.31 = 2.25
N : 2.31/2.31 = 1
Multiplied by 4
C : H : N = 9 : 9 : 4
The empirical formula : C₉H₉N₄
(C₉H₉N₄)n=346.40 g/mol
(12.0096 x 9 + 1.00784 x 9 + 14.0067 x 4)n=346.4
(108.0864+9.07056+56.0268)n=346.4
(173.184)n=346.4
n=2
The molecular formula : C₁₈H₁₈N₈
A 1.0 mol sample of he(g) at 25 is mixed with a 1.0 mol sample of Xe(g) at 50 C. What would be the changes in average kineeteic energy and the average speed of the Xe atoms that will occur as the mixture approaches thermal equilibrium?
Answer:
Explanation:
The average kinetic energy for an ideal gas is directly proportional to the temperature. The average kinetic energy of the gas is a measure of the temperature of the gas molecule
Also, the average speed is usually proportional to the square root of temperature.
Similarly, there is a noticeable increase in K.E and speed in regard to temperature but sometimes it is not usually proportional.
However, provided that there is more temperature in Xe as compared to He, then after the mixture of both takes place at equilibrium; the temperature tends to fluctuate between (25 - 50)°C
Thus, since there is a decrease in temperature in Xe, both the average kinetic energy as well as the speed too will also decrease.
What kind of electrons
An attachment
How many grams of sodium chloride should you theoretically produce if you start with 5.00 grams of calcium chloride and excess sodium carbonate? (answer in numbers only - no units or words)
Answer:
5.27 g of NaCl
Explanation:
The balanced equation for the reaction is given below:
Na₂CO₃ + CaCl₂ —> 2NaCl + CaCO₃
Next, we shall determine the mass of CaCl₂ that reacted and the mass of NaCl produced from the balanced equation. This can be obtained as follow:
Molar mass of CaCl₂ = 40 + (35.5×2)
= 40 + 71
= 111 g/mol
Mass of CaCl₂ from the balanced equation = 1 × 111 = 111 g
Molar mass of NaCl = 23 + 35.5
= 58.5 g/mol
Mass of NaCl from the balanced equation = 2 × 58.5 = 117 g
Summary:
From the balanced equation above,
111 g of CaCl₂ reacted to produce 117 g of NaCl.
Finally, we shall determine the theoretical yield of NaCl. This can be obtained as follow:
From the balanced equation above,
111 g of CaCl₂ reacted to produce 117 g of NaCl.
Therefore, 5 g of CaCl₂ will react to produce = (5 × 117)/111 = 5.27 g of NaCl.
Thus, the theoretical yield of NaCl is 5.27 g.