Answers
Answer:
Endothermic, positive
Explanation:
Related Questions
Sometimes in lab we collect the gas formed by a chemical reaction over water (see sketch at right). This makes it easy to isolate and measure the amount of gas produced.
Suppose the CO gas evolved by a certain chemical reaction taking place at 55 degree C is collected over water, using an apparatus something like that in the sketch, and the final volume of gas in the collection tube is measured to be 117 ml.
Calculate the mass of CO that is in the collection tube. Round your answer to 2 significant digits. You can make any normal and reasonable assumption about the reaction conditions and the nature of the gases.
Answers
Answer:
The correct answer is 0.12 grams.
Explanation:
The mass of carbon monoxide or CO collected in the tube can be determined by using the ideal gas equation, that is, PV = nRT.
Based on the given question, P or the pressure of the gas is given as 1 atm, volume of the gas collected in the tube is 117 ml or 0.117 L.
The number of moles or n can be determined by using the equation, mass/molar mass.
R is the universal gas constant, whose value is 0.0821 L atmK^-1mol^-1, and temperature is 55 degree C or 328 K (55+273).
On putting the values we get:
n = PV/RT
= (1 atm*0.117 L) / (0.0821 L atmK^-1mol^-1 * 328 K)
= 0.0043447 mol
Therefore, mass of CO will be moles * molar mass of CO
= 0.0043447 mol * 28 g/mol
= 0.12 g
If a 1.45 M solution has 2.43 g HCl dissolved, what is the volume of solution? (Change g HCl into mol using molar mass)
Answers
Answer: The volume of solution is 0.0459 L
Explanation:
Molarity of a solution is defined as the number of moles of solute dissolved per liter of the solution
[tex]Molarity=\frac{n}{V_s}[/tex]
where,
n = moles of solute
[tex]V_s[/tex] = volume of solution in L
moles of HCl (solute) = [tex]\frac{\text {given mass}}{\text {Molar mass}}=\frac{2.43g}{36.5g/mol}=0.0666[/tex]
Now put all the given values in the formula of molality, we get
[tex]1.45M=\frac{0.0666}{V_s}[/tex]
[tex]V_s=\frac{0.0666}{1.45}=0.0459[/tex]
Therefore, the volume of solution is 0.0459 L
the rule of eight chemistry
Answers
Answer:
octet rule
Explanation:
It refers to the tendency of atoms to prefer to have eight electrons in the valence shell.
What is the molar mass of ethanol (C2H60)?
Answers
Answer:
46.07 g/mol is the molar mass of ethonal
PLEASE help! BRAINLIEST to correct answer!
Answers
Answer:
C
Explanation:
Answer:
I think its q
Explanation:
h is the Planck constant, c the speed of light
A sample of helium gas at room temperature is compressed from 100 cm3 to 20 cm3. Its new pressure is now 30 cm Hg. What was the original pressure of the gas?
Answers
Answer:
6 cm Hg
Explanation:
Boyles Law: P1V1=P2V2
(100 mL)(x)=(20 mL)(30 cm Hg)
x = 6 cm Hg
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Which characteristic of a substance is considered a chemical property
Answers
Answer:
c
Explanation:
What is the molarity of a solution in
which 3.8 moles of sodium chloride
(NaCl) is dissolved in water to a final
volume of 2.5 L?
Answers
Answer:
1.52M in NaCl
Explanation:
Molarity = moles solute / volume solution in Liters
=> molarity (M) = 3.8 moles / 2.5 Liters solution = 1.52 molar solution in NaCl
Answer: 1.52
Explanation:
How many moles
are equal to
4.11x1023
molecules of
CO2?
Answers
Explanation:
6.02×1023 culture atoms have a mass of 63.5g. 12.0g. c +23.0g O2__44.0g CO2.(12.0+16.0+16.0=44.0g).1 mol 1 mol. 1 mol number molecules weight
The number of molecules in one mole of carbon dioxide is 6.02 × 10²³. Therefore, the number of moles of carbon dioxide which contains 4.11 × 10²³ molecules is 0.68.
What is Avogadro number ?The number of atoms that constitutes one mole of a substance is called Avogadro number. It is equal to 6.02 × 10²³. Thus, one mole of every elements contains Avogadro number of atoms.
Similarly, one mole of a compound contains 6.02 × 10²³ number of molecules. Thus, one mole of carbon dioxide contains these much molecules.
Given the number of molecules of carbon dioxide = 4.11 × 10²³
Then, no.of moles = number of molecules/ Avogadro number.
no.of moles = 4.11 × 10²³ /6.022 × 10²³ = 0.68.
Therefore, the number of moles of CO₂ that contains 4.11 × 10²³ molecules is 0.68.
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Which of the following 0.5 M aqueous salt solutions will have a pH of 7.0 at
LiF RbBr NaClO4 NH4Cl
A) LiF only B) NaClO4 only C) LiF and RbBr D) RbBr and NaClO4
Answers
Answer:
LiF and RbBr
Explanation:
Salt is an ionic compound that is made from the reaction of an acid and a base solution. Salts dissolve in water to give solutions that are acidic, basic, or neutral.
Salt formed from a strong acid and a weak base will make an acidic solution when added to water. The reason this occurs is because when the salt dissociates, the conjugate acid of the weak base will donate a proton, or one hydrogen ion, to water and form hydronium ion.
If a salt is formed from a weak acid and a strong base, it dissolves in water and the conjugate base of the weak acid will accept a proton from water and yield the hydroxide ion. Hence the solution of the salt will be basic.
If the salt is formed from a strong acid and a strong base, the salt is neutral when dissolved in water. Both LiF and RbBr are formed from strong acids and strong bases hence they will have a pH of 7.0 in solution.
LiF RbBr NaClO4 NH4Cl is = LiF and RbBr The correction is 'C'.
What are the Salt solutions?
Salt is an ionic mixture that is made from the reaction of an acid and a base resolution. Salts liquefy in water to give solutions that are acidic, basic, or neutral.
Salt constructed from a strong acid and a breakable base will make an acidic solution when added to water. The reason this occurs is that when the salt dissociates, the conjugate acid of the weak base will donate a proton, or one hydrogen ion, to water and form a hydronium ion.
If a grain of salt is formed from a weak acid and a powerful ground, it liquefies in water and the conjugate bottom of the weak acid will accept a proton from water and yield the hydroxide ion. Therefore, the solution of the salt will be basic.
If the salt is formed from a strong acid and a strong bottom, the salt is neutral when liquefied in water. Both LiF and also RbBr are formed from strong acids and powerful bases hence they will have a pH of 7.0 in resolution.
Therefore, the Correct option is 'C'
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4. A taxi ride costs $5 plus .75 cents per mile. If I
ride for 120 miles, how much will be charged?
Answers
Answer:
$95
Explanation:
.75 x 120 = 90
90+5 = 95
HELP PLEASE ILL GIVE 25 pointsWhich of the following practices could help reduce erosion of water banks? a. buffer strips b. natural fertilizers and pesticides c. decrease in fossil fuel emissions d. all of the above Please select the best answer from the choices provided A B C D
Answers
Answer:
A. Buffer strips
Explanation:
The practice that could help reduce erosion of water banks is buffer strips.
What is erosion?Erosion is the action of surface processes that removes soil, rock or dissolved material from one location on the Earth's crust, and then transports it to another location where it is deposited.
One of the practices that could be used to reduce the effect of erosion is buffer strips.
What buffer strips do is slow and filter storm runoff while helping to hold soil in place.
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The glass of a lit 75-watt incandescent bulb is hotter to the touch than the glass of a 25-watt compact fluorescent (CFL) bulb that emits the same amount of light. What could be a reason for this
Answers
CFL bulbs on the other hand are 7-10% efficient and thus need less Watts to supply the same light to that of the aforementioned bulb.
18.35 mL of an HCN solution were titrated with 35.4mL of a 0.268M NaOH solution to reach the equivalence point. What is the molarity of the HCN solution
Answers
Answer:
0.517
Explanation:
HCN + NaOH → NaCN + H2O [balanced as written]
(35.4 mL) x (0.268 M NaOH) x (1 mol HCN / 1 mol NaOH) / (18.35 mL HCN) = 0.517 M HCN
Answer: 0.517
Explanation:
Two identical light bulbs are connected to a battery in a series circuit.
An ammeter is wired into the circuit at measures a current of the
battery to be 0.5 Amps. The two light bulbs are then wired in parallel.
The ammeter shows that the current:
Answers
Answer:
0.10 amps
Explanation:
At constant pressure, what generally happens to the solubility of solids and gases when the temperature of a solution is increased?
A. The solubility of solids and gases increases.
B. The solubility of solids and gases decreases.
C. The solubility of solids increases, and the solubility of gases decreases.
D. The solubility of solids decreases, and the solubility of gases increases.
Answers
Answer:
C)
Explanation:
JUST DID IT
Answer:
A D E
Explanation:
just did it
What mass of aluminum is produced by the decomposition of 5.0 kg? How many moles of oxygen are produced?
Answers
Answer:
2.6 × 10³ g Al
74 mol O₂
Explanation:
Aluminum oxide decomposes into aluminum and oxygen, according to the following balanced equation.
2 Al₂O₃ ⇒ 4 Al + 3 O₂
Step 1: Calculate the moles corresponding to 5.0 kg of aluminum oxide
The molar mass of aluminum oxide is 101.96 g/mol.
[tex]5.0 \times 10^{3} g \times \frac{1mol}{101.96g} = 49mol[/tex]
Step 2: Calculate the mass of aluminum formed
We will use the following relations.
The molar ratio of Al₂O₃ to Al is 2:4The molar mass of Al is 26.98 g/mol[tex]49molAl_2O_3 \times \frac{4molAl}{2molAl_2O_3} \times \frac{26.98gAl}{1molAl} = 2.6 \times 10^{3} gAl[/tex]
Step 3: Calculate the moles of oxygen produced
The molar ratio of Al₂O₃ to O₂ is 2:3. Then,
[tex]49molAl_2O_3 \times \frac{3molO_2}{2molAl_2O_3} =74molO_2[/tex]
The largest contributed to water pollution is
Answers
Answer:
this si from google hope it helps
Explanation:
The Main Causes of Water Pollution in the U.S.
Runoff from Agricultural Operations. Agriculture represents one of the biggest sources of water pollution in the country. ...
Runoff and Nonpoint Source Pollution. ...
Industrial Activities. ...
Leakage from Underground Storage and Piping. ...
Leaking Sewers. ...
Vehicle Emissions. ...
Landfill Leakage. ...
Hazardous Waste.
Answer:
Runoff and Non-point Source Pollution.
Explanation:
it's caused by rainfall or snow-melt moving over and through the ground. As the runoff moves, it picks up and carries away natural and human-made pollutants, finally depositing them into lakes, rivers, wetlands, coastal waters and ground and NPS is it's abbreviation.
What is the correct IUPAC name for Ag₂S?
Answers
Answer:
Acanthite. MFCD00003406
Explanation:
The change in entropy, ΔS∘rxn , is related to the the change in the number of moles of gas molecules, Δngas . Determine the change in the moles of gas for each of the reactions and decide if the entropy increases, decreases, or has little or no change. A. 2H2(g)+O2(g) ⟶ 2H2O(l) Δngas= mol The entropy, ΔS∘rxn , increases. decreases. has little or no change.
Answers
Explanation:
Entropy of a reaction ΔS∘rxn is the degree of disoderliness in a system. Gases generally have a higher degree of disorder compared to liquids. Hence for the reaction 2H2(g)+O2(g) ⟶ 2H2O(l), the entropy decreases sice the reactants are in the gaseous state and the products is in the liquid state of matter
At what temperature will a gas be, if you allow it to expand from its original volume of 756 mL at 65.0 °C to 1.40 L? (hint volume needs to be the same)
Answers
Answer:
120.4 gradius Celcius
Explanation:
Please see the step-by-step solution in the picture attached below.
Hope this answer can help you. Have a nice day!
If a solution has a pOH=12, what is its pH?
Answers
Answer:
2
Explanation:
pH+pOH=14
- Hope that helps! Please let me know if you need further explanation.
Answer:
2
Explanation:
Ph+PoH=14
What is the mass defect of a mole of nuclei with 1.8 x 10^15 J/mol binding
energy?
Answers
Answer:
2.0 x 10^-2 kg/mol
Explanation:
which would dissolve faster individual salt crystals a big block of salt
Answers
Answer:
Table salt (the iodine isn't important) consists of much smaller particles than rock salt and therefore has a much higher ratio of surface area to mass. Since chemical reactions occur at surfaces,the smaller table salt particles will dissolve far more quickly than the larger rock salt.
Explanation:
Answer:
Individual salt crystals
Explanation:
A given quantity of solute dissolves faster when it is ground into small particles than if it is in the form of a large chunk because more surface area is exposed.
Give me a good review if right please.
Which of the following statements about an S N1 reaction mechanism is true? The reaction involves two steps and occurs fastest with tertiary alkyl halides. The reaction involves one step and occurs fastest with tertiary alkyl halides. The reaction involves one step and occurs fastest with primary alkyl halides. The reaction involves two steps and occurs fastest with primary alkyl halides.
Answers
Answer:
The reaction involves two steps and occurs fastest with tertiary alkyl halides
Explanation:
To solve such this we must know the concept of nucleophilic substitution reaction. The reaction involves two steps and occurs fastest with tertiary alkyl halides. Therefore, the correct option is option A.
What is chemical reaction?Chemical reaction is a process in which two or more than two molecules collide in right orientation and energy to form a new chemical compound. The mass of the overall reaction should be conserved. There are so many types of chemical reaction reaction like combination reaction, double displacement reaction.
The characteristics of SN1 mechanism:
SN1 reaction is a nucleophilic substitution reaction.
Leaving group, a nucleophile, electrophile and a solvent are present
Two types of enantiomers can be formed in the reaction depending on the preference of the nucleophile.
The first step is the slowest because a bond is being broken.
SN1 reaction involves two steps and occurs fastest with tertiary alkyl halides
Therefore, the correct option is option A.
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A student wants to examine a substance without changing its identity. Which of the following properties should the student examine?
Answers
Answer:
A. Ductility, because it can be observed by altering the shape of the substance
Explanation:
Changing the shape of a substance does not change its identity.
What are 3 stages of the water cycle are
Answers
5) Low iron concentration (as low as 0.02 nM) in the open ocean limits phytoplankton growth. Preconcentration is required to determine such low concentrations. Trace Fe3 from a large volume of seawater is concentrated onto a 1.2 mL chelating resin column, the column is then rinsed with 30 mL of high purity water and eluted with 10 mL of 1.5 M high purity HNO3. a.) For each sample, seawater is passed through the column of 17 h at 10 mL./min. How much is the concentration of Fe3 in the 10 mL of HNO3 eluate increased by this preconcentration procedure
Answers
Answer:
Check the explanation
Explanation:
Sample volume V= 10 mL/min x 17 h x 60 min/h / 1000 mL/L = 10.2 L
The concentration is increased
10200 mL (sample volum) / 10 mL (eluted sample) = 1020 times.
57x10-9 M / 1020 = 5.6x10-12 M
1.5 M HNO3 will contain ≤ 2ppm x (1.5M/15.7M ) ≤ 0.190 ppm ≤ 190 ppb
Ignoring this is reagent impurity and calculating for sea water
≤ 190 ppb /1020 = 0.186 ppb = 0.186 x 10-9g/mL = 0.186 x 10-6g/L =
0.186 x 10-6g/L / 56 g/mol = 0.003 x10-6 M = 3 nM
Which of the following describes the change in atomic mass and atomic number during this reaction?
Answers
A solution of KOH has a [OH-] concentration of 0.045 M. What is the pOH of the solution? *
1 point
-1.3
1.3
1.1
0.90
what is the answer?
Answers
Answer:
[tex]pOH=1.3[/tex]
Explanation:
Hello,
In this case, since pH is computed by knowing the concentration of hydrogen ions, one could compute the pOH by knowing the concentration of the hydroxyl ions as in this case which is 0.045M as shown below:
[tex]pOH=-log([OH^-])=-log([0.045])\\\\pOH=1.3[/tex]
Best regards.
Answer:
The pOH of the 0.045 M solution is 1.3
The second option (1.3) is correct
Explanation:
Step 1: Data given
Concentration [OH-] of KOH is 0.045 M
Step 2: Calculate pOH
pOH = -log[OH-]
pOH = -log (0.045)
pOH = 1.3
The answer:
The pOH of the 0.045 M solution is 1.3
The second option (1.3) is correct
