54.15 g
First you start out with the equation n=cv (n= moles, c=molarity, v= volume)
You’re going to multiply 0.10M by 3.30L to get an answer of 0.33 moles of Ca(NO3)2
From there you’re gonna convert the moles to grams to get your answer, first you have to find the molar mass of Ca(NO3)2
This can be done by finding adding the molar mass of each individual substance
The answer you should get for the molar mass is 164.1 g
From there just multiply the number of moles you calculated (0.33 mol) by the molar mass (164.1 g) and your answer is going to be 54.15 g Ca(NO3)2
We first consider the gases that will be present in that sample.
First, there will be nitrogen, as stated. Second, there will also be water in the form of water vapor. For this, we need the vapor pressure of water at 23.0 °C, which is about 21.0 mmHg. Now, the sum of the vapor pressures of the gases will be equivalent to the total pressure. So the pressure of nitrogen gas is:
785 - 21
= 764 mmHg
Answer:
b) 2.0 mol
Explanation:
Given data:
Number of moles of Ca needed = ?
Number of moles of water present = 4.0 mol
Solution:
Chemical equation:
Ca + 2H₂O → Ca(OH)₂ + H₂
now we will compare the moles of Ca and H₂O .
H₂O : Ca
2 : 1
4.0 : 1/2×4.0 = 2.0 mol
Thus, 2 moles of Ca are needed.
