Read the chemical equation. Mg + HCI - MgCl2 + H2
How many liters of hydrogen gas is produced at 298 K and 0.940 atm if 4.00 moles of hydrochloric acid react with an excess of magnesium metal?
O 26.0 liters
O 52.1 liters
82.3 liters
104 liters

74.04 liters of hydrogen gas are produced.

Explanation: According to reaction, 2 mol of HCl gas gives 1 mole of hydrogen gas, then 6 moles of HCl gas will give: moles of hydrogen gas that is 3 moles.

The pressure of the hydrogen gas at 298 K = 0.990 atm

The volume occupied by the hydrogen gas = V

Number of hydrogen has moles = 3 moles

PV=nRT

V = 74.04 L

74.04 liters of hydrogen gas are produced.

- calcium has greater affinity to bond with electron receptors than hydrogen does and hence, it has the ability to replace hydrogen in most of its compounds.

- lithium has 2 valence electrons in the product because it can make only 1 bond with hydrogen. beryllium has 4 valence electrons in the product because it can only make 2 bonds. it has fewer electrons than neon and can react with electron donors. each hydrogen has 2 valence electrons, the same as helium.

- the covalent bond formed between carbon and hydrogen is polar because carbon is more electronegative than hydrogen and it attracts the bonded electron pair closer to itself, thus giving hydrogen a partial positive charge.

- a hydrogen bond is a relatively weak bond that hydrogen atoms make with the electronegative atoms nitrogen, oxygen or fluorine.

so the best choice is a.) 2 calcium (ca) atoms