Question

Question 5 (1 point) If (1.69x10^1) g of silicon react with (3.402x10^1) g of chlorine gas to form silicon tetrachloride. What mass of silicon tetrachloride forms? Note: Your answer is assumed to be reduced to the highest power possible. Your Answer: Answer

Answer 1

5)

Molar mass of Si = 28.09 g/mol

mass(Si)= 16.9 g

use:

number of mol of Si,

n = mass of Si/molar mass of Si

=(16.9 g)/(28.09 g/mol)

= 0.6016 mol

Molar mass of Cl2 = 70.9 g/mol

mass(Cl2)= 34.02 g

use:

number of mol of Cl2,

n = mass of Cl2/molar mass of Cl2

=(34.02 g)/(70.9 g/mol)

= 0.4798 mol

Balanced chemical equation is:

Si + 2 Cl2 ---> SiCl4

1 mol of Si reacts with 2 mol of Cl2

for 0.6016 mol of Si, 1.203 mol of Cl2 is required

But we have 0.4798 mol of Cl2

so, Cl2 is limiting reagent

we will use Cl2 in further calculation

Molar mass of SiCl4,

MM = 1*MM(Si) + 4*MM(Cl)

= 1*28.09 + 4*35.45

= 169.89 g/mol

According to balanced equation

mol of SiCl4 formed = (1/2)* moles of Cl2

= (1/2)*0.4798

= 0.2399 mol

use:

mass of SiCl4 = number of mol * molar mass

= 0.2399*1.699*10^2

= 40.76 g

Answer: 4.08*10^1 g

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