Sarthaks Test
+1 vote
1.9k views
in Chemistry by (29.7k points)

(a) Calculate the number of moles in 112 g of iron. 

(b) Calculate the mass of 0.5 moles of sugar (C12H22O11). 

(c) Define the term molecular mass. 

(d) Determine the molecular mass of ZnSO4

[Atomic mass of Zn = 65 u, S = 32 u, O = 16 u] 

(e) Calculate the number of molecules of carbon dioxide, present in 4.4 g of CO2

[Atomic mass of C = 12 u, O = 16 u, NA = 6.022 × 1023 mol−1

1 Answer

+2 votes
by (128k points)
selected by
 
Best answer

(a) 1 mole of iron (Fe) = 56 g (molar mass) 

Since 56 g of iron = 1 mol 

Therefore, 112 g of iron= 1/ 56 ×112 mol = 2 mol 

(b) Molar mass of C12H22O11 = (12 × 12) + (22 × 1) + (11 × 16) = 342 g 

Since mass of 1 mole of sugar = 342 g of sugar 

Therefore mass of 0.5 mole of sugar = 342 × 0.5 = 171 g 

(c) Molecular mass: Molecular mass is the sum of the atomic masses of all the atoms in a molecule of that substance. 

(d) Molecular mass of ZnSO4 = (1 × 65) + (1 × 32) +(4 ×16) = 161 g 

(e) Molecular mass of CO2 = 12 + 2 × 16 = 44 g 

Since 44 g of CO2 contains 6.022 × 1023 molecules 

Therefore, 4.4 g of CO2 contains = 6.022×1023 /44 ×4.4 = 6.022 × 1022molecules

Welcome to Sarthaks eConnect: A unique platform where students can interact with teachers/experts/students to get solutions to their queries. Students (upto class 10+2) preparing for All Government Exams, CBSE Board Exam, ICSE Board Exam, State Board Exam, JEE (Mains+Advance) and NEET can ask questions from any subject and get quick answers by subject teachers/ experts/mentors/students.

Categories

...