Convert 72g of water into moles of water using molecular weights.
So water is H2O so add up those molecular weights (H=1 and O=16)
2(1)+(16) = 18 g/mol
Then convert so 72g / (18 g/mol) = 4 mol
Now you can convert mol of water to mol of oxygen. So 4 mol of water is 4 mol of oxygen. Then use oxygen molecular weight to find grams again.
4 mol oxygen * 16 g/mol = 64g of oxygen
If we were doing hydrogen instead of oxygen there would be 8 mol hydrogen in 4 mol of water (2 H’s in every H2O molecule) and since we have 74 grams and oxygen is 64 grams, Hydrogen should be 8 grams. Math to check below
8 mol hydrogen * 1 g/mol = 8g of hydrogen
It all adds to 72 so we are correct.
The balanced chemical equation is P4+3O2--> 2P2O3
2 NH3+ 2 O2 —> 2 NO+ 3 H2O
Answer:
2835 J
Explanation:
Take the specific heat capacity of water as 4.2 J/ g°C.
Energy (heat) = mass x specific heat capacity x change in temperature
(E= mcΔT)
E = 27 x 4.2 x (45-20)
E = 2835 J
