Answer:
The accurate answer is 596.5 kJ.
Explanation:
The question specifies that the mass of ethanol, C2H5OH, is 20 grams.
The molar mass of ethanol is 46 g/mol.
To find the moles of ethanol, we use the formula:
n = mass / molar mass
= 20/46 = 0.435 moles
According to the question, the standard heat of combustion for ethanol is 1372 kJ/mol. Hence, one mole releases 1372 kilojoules during combustion.
The energy produced from burning 20 grams of ethanol completely is 0.435 * 1372 = 596.5 kJ.
Answer: The process of heating a crucible to eliminate moisture from a hydrate.
Explanation:
The available choices are:
a. Heating a solvent to aid in the dissolution of a solute.
b. Heating a solid in isolation to remove moisture.
c. Bringing water to a boil for use in a water bath.
d. Heating a crucible to eliminate moisture from a hydrate.
Possible actions that can be done on a hot plate include:
a. Heating a solvent to assist a solute in dissolving.
b. Heating a solid in isolation to dry it.
c. Heating water to boiling for a water bath.
However, it's important to note that using a hot plate for heating a crucible to remove water from a hydrate is not advisable. Silica or ceramic materials are not meant to be heated on a hot plate.
Consequently, the correct procedure is heating a crucible to remove water from a hydrate.
M1V1 = M2V2
(2.50)(100.0) = (0.550)V2
V2 = 455mL
From 100.0 mL of 2.50 M KBr, you can prepare 455 mL of 0.550 M solution.
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The result is:
The new volume is: 
Rationale:
Because the temperature remains constant, we can apply Boyle's Law to solve this issue.
Boyle's Law stipulates that:

Where,
P is the gas's pressure.
V is the gas's volume.
According to the information provided:

Let's put the values into the equation:


Consequently, the new volume is: 
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Answer:
Please review the following responses
Explanation:
1) A solution of 100. mL contains 19.5 g of NaCl (3.3M)
2) 100. mL of NaCl solution at 3.00 M (3 M)
3) A solution of 150. mL holds 19.5 g of NaCl (2.2 M)
4) The concentrations of beakers 1 and 5 are identical (1.5M)
Molar mass of NaCl = 23 + 36 = 59 g
For beaker number 3:
59 g -------------- 1 mol
19.5 g ------------- x
x = 19.5 x 1/59 = 0.33 mol
Molarity (M) = 0.33 mol/0.150 l = 2.2 M
For beaker number 4:
Molarity (M) = 0.33mol/0.10 l = 3.3 M
For beaker number 5:
Molarity (M) = 0.450/0.3 = 1.5 M