The following balanced equation shows the formation of ethane (C2H6).

C2H2 + 2H2 Right arrow. C2H6

How many moles of hydrogen are needed to produce 13.78 mol of ethane?
3.445 mol
6.890 mol
27.56 mol
55.12 mol

27.56 moles of hydrogen is required to produce 13.78 mol of ethane.

We can see that this reaction involves the hydrogenation of ethene to give ethane. Here an alkene is converted to an alkane by addition of hydrogen across the double bond.

The equation of the reaction is;

C2H2 + 2H2 > C2H6

From the balanced reaction equation;

2 moles of hydrogen is required to make 1 mole of ethane

x moles of hydrogen is required to  produce 13.78 mol of ethane

x = 2 moles ×  13.78 mol/1 mole

x = 27.56 moles

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We need 27.56 moles hydrogen to produce 13.78 mol of ethane. (option 3)

Explanation:

Step 1: Data given

Moles ethane produced = 13.78 moles

Step 2: The balanced equation

C2H2 + 2H2 → C2H6

Step 3: Calculate moles of hydrogen

For 1 mol acetylene (C2H2) we need 2 moles hydrogen (H2) to produce 1 mol of ethane (C2H6)

For 13.78 moles ethane produced we need 2*13.78 = 27.56 moles hydrogen (H2)

We need 27.56 moles hydrogen to produce 13.78 mol of ethane. (option 3)

a gas, having a molecular weight of 13 kg/kmol and a kinematic viscosity of 0.25 cm2/s, flows through a pipe 0.25 m internal diameter and 5 km long at the rate of 0.4 m3/s and is delivered at atmospheric pressure.

there are two significant figures.