Answer: 0.0250
Explanation: 10 X 0.0750 = .75
.75 / 30 = 0.0250 M
Assuming ammonia is the product of this reaction:
N2+3H2--->2NH3
2 mole N2 * (3 mol H2)/(1 mol N2)= 6 mol H2
You would need 6 mol of hydrogen gas to completely react with 2 mol of nitrogen.
Answer : The metal used was iron (the specific heat capacity is
).
Explanation :
In this problem we assumed that heat given by the hot body is equal to the heat taken by the cold body.


where,
= specific heat of unknown metal = ?
= specific heat of water = 
= mass of unknown metal = 150 g
= mass of water = 200 g
= final temperature of water = 
= initial temperature of unknown metal = 
= initial temperature of water = 
Now put all the given values in the above formula, we get


Form the value of specific heat of unknown metal, we conclude that the metal used in this was iron (Fe).
Therefore, the metal used was iron (the specific heat capacity is
).