Question

In the diagram above, identify which arrow represents the smallest electron transition in the UV region of the hydrogen emission spectrum. Answer with the correct Roman numeral.

Answer 1

Answer:

Explanation:

ubmitted by remeday86 on Thu, 01/22/2009 - 19:16

Ethanol (C2H5OH) is synthesized for industrial use by the following reaction, carried out at very high pressure.

C2H4(g) + H2O(g) ? C2H5OH(l)

What is the maximum amount of ethanol (in grams) that can be produced when 0.090 kg of ethylene (C2H4) and 0.038 kg of steam are placed into the reaction vessel?

_______ g C2H5OH

---> My work:

0.090 kg C2H4 x (1000 g C2H4/ 1 kg C2H4) x (1 mol C2H4/ 28.0533 g C2H4) = 3.208 mol C2H4

0.038 kg H2O x (1000 g H2O/ 1 kg H2O) x (1 mol H2O/ 18.0153 g H2O) = 2.11 mol H2O

...Now I am not sure what to do after  ???

Determine which one is your limiting reagent. First, look at the mole ratio of H2O to C2H4. Notice that they react in a 1:1 ratio- one mole of C2H4 reacts with 1 mole of H2O. Now take a look at how much H2O and C2H4 you actually have:

3.208 mol C2H4

2.11 mol H2O

If they react in a 1:1 mole ratio, then 3.208 moles of H2O are needed to react with 3.208 moles of C2H4. But you only have 2.11 moles of H2O! So H2O is your limiting reactant. Once you run out of H2O, you can't produce anymore ethanol.

Since H2O is your limiting reagent, it determines how much product you make, since it runs out first. According the chemical equation, when 1 mole of H2O reacts, 1 mole of C2H4 is formed. So, if you have 2.11 moles of H2O, then 2.11 moles of ethanol is formed. Now all you need to do is convert moles of ethanol into grams of ethanol and there you have it.