Calculate the percentage, by mass, of carbon in sodium hydrogencarbonate (NaHCO3)

When faced with this style of problem there are steps to correctly answer the quesion:

Step 1 - identify the atomic mass of carbon

Step 2 - calculate the atomic mass of the compound

Step 3 - work out the percentage, by mass, of carbon in the compound


Step 1:

To  calculate the atomic mass, a periodic table is required. The atomic mass of each element is located at the top of the element, displayed as a number. In this case carbon has an atomic mass of 12 g/mol.

Step 2:

The same principles in step 1 are required and applied to the remaining atoms in the compound - sodium hydrogen carbonate. The atoms in the compound are sodium (Na), hydrogen (H), carbon (C) and oxygen (O). Looking at the value of atomic mass on the periodic table, the values of atomic mass are as follows:

Na = 23 g/mol

H = 1 g/mol

C = 12 g/mol

O = 16 g/mol

There is 1 Na atom, 1 H atom, 1 C atom and 3 O atoms in the compound. Now add these values together to get the atomic mass of the compound as such:

23+1+12+(3*16) = 84 g/mol

Step 3:

Now the percentage, by mass, needs to be calculated. The general rule for calculating a percentage is:

percentage = (value/total)*100%

Therefore by applying this rule for our problem we find that

Percentage = (12/84)*100% = 14.3 % (to 1 d.p)

Hayden T. GCSE Chemistry tutor, A Level Chemistry tutor, GCSE Maths t...

1 year ago

Answered by Hayden, a GCSE Chemistry tutor with MyTutor

Still stuck? Get one-to-one help from a personally interviewed subject specialist


£22 /hr

Teresa B.

Degree: Anatomy (Bachelors) - Glasgow University

Subjects offered:Chemistry, Spanish+ 3 more

-Personal Statements-

“Since the dawn of time, I've been talking to people about things I love and enjoy. How cliché, I know. But don't roll your eyes at me yet. Hear me out: ...”

PremiumLorenzo C. GCSE Biology tutor, A Level Biology tutor, GCSE Chemistry ...
£24 /hr

Lorenzo C.

Degree: Biomedical Sciences with Honours in Infectious Diseases (Bachelors) - Edinburgh University

Subjects offered:Chemistry, Physics+ 1 more


“5th in the World at International A-Level Biology Over two years experience in tutoring!”

PremiumOliver B. GCSE Chemistry tutor, GCSE Biology tutor, GCSE Geology tuto...
£36 /hr

Oliver B.

Degree: Medicine (PhD) (Doctorate) - Bristol University

Subjects offered:Chemistry, Science+ 5 more

Extended Project Qualification
-Personal Statements-

“I have been teaching here for over 2 years and am willing to go the extra mile for any regular pupil of mine. I use varying teaching styles depending on what helps you to learn best!”

About the author

Hayden T.

Currently unavailable: for new students

Degree: MChem Chemistry (Masters) - Warwick University

Subjects offered:Chemistry, Maths+ 1 more


“About me:As a first year student at the University of Warwick studying an integrated Masters in Chemistry, I have always had a keen interest in all the sciences and maths, and enjoy these subjects at all levels of education. I aim to...”

You may also like...

Posts by Hayden

Calculate the percentage, by mass, of carbon in sodium hydrogencarbonate (NaHCO3)

What are isotopes and how do they differ from each other?

Other GCSE Chemistry questions

What is the mass (in grams) of 0.1 moles of CaCO3?

What is observed in the reaction between an acid and a carbonate?

Balance the equation for the complete combustion of hydrogen.

The relative formula mass of CaO is 56 and the relative formula mass of CO2 is 44. What is the mass of CaO that can be obtained from 200 g of CaCO3. CaO3 -> CaO + CO2

View GCSE Chemistry tutors

We use cookies to improve your site experience. By continuing to use this website, we'll assume that you're OK with this. Dismiss