Answer:
The mass of water is 18 g
Explanation:
The reaction of calcium with water can be represented in the equation below:
Ca + 2H₂O --------->Ca(OH)₂ +H₂
1 Mole of gas at STP = 22.4L
From the displacement reaction above, calculate the mass of water that will produce 22.4L of hydrogen gas at STP.
Mass of 2H₂O = 2(2x1 + 16) = 2X18 = 36 g/mol
Using proportional analysis;
36 g of 2H₂O produced 22.4 L of H₂, then
what mass of 2H₂O will produce 11.2L of H₂ ?
Mathematically,
22.4 L ----------------------------------> 36g
11.2 L -----------------------------------> ?
Cross and multiply, to obtain the expression below
= (11.2 X 36)/22.4
= 18 g
Therefore, the mass of water is 18 g
