Get insightful responses to your questions quickly and easily on IDNLearn.com. Ask your questions and receive reliable, detailed answers from our dedicated community of experts.

What percentage of the total mass of KHCO₃ is made up by nonmetallic elements? 
a. 17% 
b. 83% 
c. 61% 
d. 20% 
e. 50%


Sagot :

Mass of K = 39.1g/mole
Mass of H = 1g/mole
Mass of C = 12g/mole
Mass of O = 16g/mole
Mass of KHCO3 = 39.1 + 1 + 12 + 3*16 = 100,1g/mole

100% ------------ 100.1g of KHCO3
x% ----------------- 12g of C
x = 11,99% of C in KHCO3

100% -------------- 100.1 of KHCO3
y% --------------------3*16g of O
y = 47,95% of O in KHCO3

100% ------------- 100.1g of KHCO3
z% ---------------- 1g of H
z = 0,99% of H in KHCO3

11,99% + 47,95% + 0,99% = 60,93% ≈ 61%

answer: C