New to this Forum..Help Please

For the first one: it's the third option, it's not 4 grams

Second question, the answer is C, which is the second option. Reducing agent means that it gains electrons.

This is because, by definition, a reducing agent is one that can remove the oxygen from a particular compound, or reduce the oxidation state of that compound...(Just like how an oxidising agent is something that provides oxygen)

Here, SnO2 is getting reduced by C to Sn. The oxidation state of Sn is coming down from +4 to 0, and thus its getting reduced.

NH3 would be the base!

For the last question: From the equation, 2 moles ( 1 x 2 = 2lb) of hydrogen reacts with 1 mole (35.5 x 2 = 71lb) of Chlorine to produce 2 mole { 2(1 + 35.5} = 73 lb ) of HCl.
Therefore the answer is 35.50 x 2 = 71lb.

Check out this post: https://biology-forums.com/index.php?topic=4883.0

Thank you Howard!!!!  Got an 18/20.

Nice, let us know if you need more help!