Answer:
Explanation:
So, the formula for the compound should be:

Now we assume that we have 1 mol of substance, so we can make calculations to know the molar mass of element X, as follows:

So we have that 6 moles weight 212.7g, and we can make a rule of three to know the weight of compound X:

As we used 1 mol, we know that the molar mass is 32.06g/mol
So the element has a molar mass of 32.06 g/mol and an oxidation state of +6, with this information, we can assure that the element X is sulfur, so the compound is 
(3.5mol)(24.106 g/1mol c6h6) =84.371 g C6H6
Answer:
406.45mL
Explanation:
The following data were obtained from the question:
V1 = 350mL
P1 = 720mmHg
P2 = 630mmHg
V2 =?
The new volume can be obtain as follows:
P1V1 = P2V2
720 x 350 = 620 x v2
Divide both side by 620
V2 = (720 x 350) /620
V2 = 406.45mL
The new volume of the gas is 406.45mL