I just had this question. The answer is A. a battery
Answer:
2.24dm³
Explanation:
Given parameters:
Mass of He = 40g
Unknown:
Volume of Helium = ?
Solution:
To solve this problem, we convert the given mass to number of moles.
Number of moles =
molar mass of He = 4g/mol
Number of moles =
= 0.1mole
So;
1 mole of gas at rtp occupies a volume of 22.4dm³
0.1 mole of He will occupy a volume of 0.1 x 22.4 = 2.24dm³
Answer:
B
Explanation:
When it freezes, it will be a solid. The molecules will barely move, not as much as in the other answer choices.
KOH is a strong base, so [OH-] = 0.10 M = 1.0 x 10^-1 M
[H+][OH-] = Kw
Kw = 1.0 x 10^-14
[H+] = 1.0 x 10^-14 / 1.0 x 10^-1 = 1.0 x 10^-13 M