2H2(g)+O2(g) ---> 2H2O(l)
delta H= -572kJ/mole of O2
Calculate the amount of heat evolved when 10g of hydrogen are burned in excess oxygen.
Can someone please explain step by step? =D
I worked this for you below. You didn't look or you don't understand? If you don't understand, go step by step and be specific about what you don't understand.
I looked at the solution from below but i do not understand where the 4g of H2 came from and why 572kJ x 10/4?
Would you mind explaining please? I'm quite new to this topic.
Look at the equation.
2H2 + O2 ==> 2H2O
2 mols H2 react with 1 mol O2.
That's 4 g H2 (4*1 = 4) react with 32 g O2 (2*16=32).
So you would get 572 kJ if you had 32 g O2 or 4 g H2. Suppose you had 4 g H2. You would have
572 x 4/4 = ?
Suppose you had twice as much H2 (8 g H2)?
You would obtain twice as much or 572 x 2 = ? How do you get that? It's 572 x (8/4) = ?
If you have 10 g it's 572 x (10/4) = ?
What about apples? If apples cost 5.72 for 4 apples, how much will 10 apples cost? That's $5.72 x (10/4) = ?
Thank you very much, I understand now (:
Sure! To calculate the amount of heat evolved when 10g of hydrogen are burned in excess oxygen, we need to follow these steps:
Step 1: Determine the molar mass of hydrogen (H2).
The molar mass of hydrogen is 2 grams/mol.
Step 2: Convert the given amount of hydrogen (10g) to moles.
To do this, divide the given mass by the molar mass:
10g / 2g/mol = 5 moles of hydrogen (H2).
Step 3: Use the balanced equation to determine the moles of water formed.
According to the balanced equation: 2H2(g) + O2(g) → 2H2O(l)
We can see that 2 moles of hydrogen (H2) react to form 2 moles of water (H2O).
So, 5 moles of hydrogen (H2) will react to form 5 moles of water (H2O).
Step 4: Calculate the heat evolved using the given delta H value.
The given delta H value is -572 kJ/mole of O2.
Since 1 mole of oxygen (O2) reacts to form 2 moles of water (H2O), we need to multiply the delta H value by 2:
-572 kJ/mole × 2 moles of H2O = -1144 kJ.
Therefore, when 10g of hydrogen are burned in excess oxygen, the amount of heat evolved is -1144 kJ.