# Chemistry

posted by .

Acetylene (C2H2) and hydrogen fluoride (HF) react to give difluoroethane:
C2H2+2HF->C2H4F2
When 2.3 mol of C2H2 and 12 mol HF are reacted in a 15.4 L flask, what will be the pressure in the flask at 13°C when the reaction is complete?

I know I'm supposed to find the limiting reagent, and use the formula PV=nRT; but I'm not clear on how to find the limiting reagent yet.

• Chemistry -

I find the limiting reagent by solving two simple stoichiometry problems. I use one reagent and find the product, then the other reagent and find the product. Convert 2.3 mol C2H4 to moles of the product.
2.3 mols C2H4 x (1 mole C2H4F2/1 mole C2H2) = 2.3 x (1/1) = 2.3 mols C2H4F2.

Then do the same for HF.
12 moles HF x (1 mole C2H4F2/2 moles HF) = 12 x (1/2) = 6 moles C2H4F2
Obviously both answers can't be right; the correct one in limiting reagent problems is ALWAYS the smaller one. In this case, the limiting reagent is C2H2 and there will be 2.3 moles C2H4F2 formed.

## Similar Questions

1. ### Chemistry

Acetylene, C2H2, can be converted to ethane, C2H6, by a process known as hydrogenation. The reaction is: C2H2(g) + 2H2(g) === C2H6(g) Given the following, what is the Kp for the reaction?
2. ### Intro Chemistry

Given: C2H2(g) +2HF(g) -> C2H4F2(g) Find: pressure in a 10.0L flask when the reaction is complete When 1.0 mol of C2H2 and 5.0 mol pf HF are reacted in a 10.0 L flask, what will be the pressure in the flask at 0 degrees C when the …
3. ### Chemistry

Calculate how much acetylene (C2H2) can be produced from 358 g of H20 and an excess of CaC2 if the perfect yield for this reaction is 94.5% CaC2+H2)-> C2H2+C2H2+CA(OH)2
4. ### CHEMISTRY

If heat of combustion of acetylene C2H2 is -1301.1 kJ/mol then : a) Write balanced thermochemical equation of acetylene combustion b) If 0.25 mol C2H2 reacted according to the previous equation , and what is the emitted energy ?
5. ### Chemistry

Please also, help me set up this problem. Acetylene, C2H2, can be converted to ethane, C2H6, by a process known as hydrogenation. The reaction is C2H2(g)+2H2(g)⇌C2H6(g). Given the following data at standard conditions (all pressures …
6. ### chemistry

Calcium carbide (CaC2) reacts with water to form acetylene (C2H2) gas and calcium hydroxide (Ca(OH)2). If the ΔH for: CaC2(s) + 2H2O(l) = Ca(OH)2(s) + C2H2(g) is -127 kJ, then what is the enthalpy of formation for calcium carbide?
7. ### chemistry

If 6.20 mol of calcium carbide (CaC2) reacts with an excess of water, how many moles of acetylene (C2H2), a gas used in welding, will be produced?
8. ### Chemistry

Need Help! 1. Ammonia is produced by the reaction of hydrogen and nitrogen. N2(g)+3H2(g)→2NH3(g)ammonia How many moles of N2 reacted if 0.65mole NH3 is produced?
9. ### Chemistry

Oxyacetylene torches are fueled by the combustion of acetylene, C2H2. 2C2H2(g) + 5O2(g) --> 4 CO2(g) + 2H2O(g) If the enthalpy change for the reaction is -2511.14 kJ/molrxn, how much heat can be produced by the reaction of a. 2mol …
10. ### Chem

If 4.70 mol of calcium carbide (CaC2) reacts with an excess of water, how many moles of acetylene (C2H2), a gas used in welding, will be produced?

More Similar Questions