30 mL of hydrogen and 20 mL of oxygen react to give water. What is left at the end of the reaction?

Q. 36 1ml of hydrogen peroxide gives 10 ml of oxygen at BTP. I t is a)10 vol hydrogen peroxide b)20 vo of hydrogen peroxide 3)30 vol of hydrogen peroxide 4)40 vol of hydrogen peroxide

Q. Volume of one molecule of oxygen gas at S.T.P. is (1) 3.7 × 10–20 mL (2) 2.5 × 10–21 mL (3) 3.1 × 10–22 mL (4) 6.1 × 10–23 mL

Q. 100 ml of hydrogen combine with 50 ml of oxygen to give 100 ml of water vapour. This statement is according to:

Q. $10$ mL of hydrogen combines with $5$ mL of oxygen to yield water. When $200$ mL of hydrogen at STP is passed over heated $CuO$, the $CuO$ loses $0.144$ g of its weight. State the law illustrated by these chemical combinations.

Q. 10 mL of hydrogen combine with 5 mL of oxygen to yield water. When 200 mL of hydrogen at NTP is passed over heated CuO, the CuO loses 0.144 g of its mass. Do these data correspond to the law of constant proportions?