The flame in a torch used to cut metal is produced by burning acetylene (C2H2) in pure oxygen. Assuming the combustion of 1 mole of acetylene releases 1251 kJ of heat, what mass of acetylene is needed to cut through a piece of steel if the process requires 95.5 × 104 kJ of heat?

19.8 kg of C₂H₂ is needed

Explanation:

We solve this by a rule of three:

If 1251 kJ of heat are relased in the combustion of 1 mol of acetylene

95.5×10⁴ kJ of heat may be released by the combustion of

(95.5×10⁴ kJ . 1) /1251kJ = 763.4 moles of C₂H₂

Let's convert the moles to mass → 763.4 mol . 26 g/1 mol = 19848 g

If we convert the mass from g to kg →  19848 g . 1kg / 1000g = 19.8 kg

We need 19.88 kg of acetylene

Explanation:

Step 1: Data given

The combustion of 1 mole of acetylene releases 1251 kJ of heat

Step 2: Calculate moles acetylene needed

If we burn 1 mol, there is 1251 kJ released

If we burn x moles there is 95.5 *10^4 kJ

x = 95.5 *10^4 / 1251  

x = 763.4

If we burn 763.4 moles there is 95.5 *10^4 kJ released

Step 3: Calculate mass acetylene

Mass acetylene = moles * molar mass

Mass acetylene = 763.4 moles * 26.04 g/mol

Mass acetylene = 19878.9 grams = 19.88 kg

We need 19.88 kg of acetylene

the positions which points up in upward carbon and down in downward carbon are axial

and vice versa holds true for equatorial positions

so the correct answer with labelled diagram will be