Answer:
Explanation:
Regardless of the type of gas, 1 mole at standard temperature and pressure (STP) occupies a volume of 22.4 liters. In this case the gas is helium (He).
We can set up a ratio.
Multiply by the given number of moles.
The moles of helium will cancel.
Multiply.
5.25 moles of helium gas at STP is 117.6 liters of helium.
<h2><u>Answer:</u></h2>
The correct answer is A) 1.04 mol Cu
{65.8 g / 63.55 g/mol}
= 1.04 mol Cu
Explanation:
In 63.55 g of copper metal there are 1 m
o
l of C
u atoms. By dividing the mass of Cu and molar mass, we can easily get the number of moles.
The following are the answers to the different questions:
<span>The four rows of data below show the boiling points for a solution with no solute, sucrose (C12H22O11), sodium chloride (NaCl), and calcium chloride (CaCl2) (not in that order). Which boiling point corresponds to calcium chloride?
A. 101.53° C
Which of the following solutions will have the lowest freezing point?
D. 1.0 mol/kg magnesium fluoride (MgF2)
Which of the following compounds will be most effective in melting the ice on the roads when the air temperature is below zero?
A. sodium iodide (NaI)
Four different solutions have the following vapor pressures at 100°C. Which solution will have the greatest boiling point?
B. 96.3 kPa
Four different solutions have the following boiling points. Which boiling point corresponds to a solution with the lowest freezing point?
D. 108.1°C</span>
Answer:
Positive: a and b
Negative: c
Explanation:
The entropy (S) is the measure of the randomness of the system, and it intends to increase. The randomness can be determined by the energy of the molecules, their velocity and how distance they are between the other molecules.
When the entropy increases, ΔS is positive, when the entropy decreases, ΔS is negative. So, when gasoline mix with air in a car engine, the process intends to continue, the randomness increases and ΔS is positive. When hot air expands, the distance between the molecules increases, so ΔS is positive.
But, when humidity condenses, the molecules stay closer, so there's a decrease in the randomness, then ΔS is negative.
