633.97 L
Explanation:
Well use the combined gas law;
P₁V₁T₁ = P₂V₂T₂
We need to change the temperatures into Kelvin;
18.9°C= 292.05 K
5.9°C = 279.05 K
756 * 512 * 292.05 = 639 * V₂ * 279.05
113,044,377.6 = 178,312.95 V₂
V₂ = 113,044,377.6 / 178,312.95
V₂ = 633.97 L
Kindly checkout the attached pic. It contains all your required questions.
There are 0.25 kilometers in 250 meters
The mass of magnesium should be less than 0.09g to enable a faster reaction rate. Magnesium reacts to form a white coating around it which stops the reaction. The lesser the gram the faster the reaction before the coating is formed. It is also advisable to use magnesium fillings to increase the rate of reaction.