How many moles of Magnesium must react with excess Oxygen to produce 80g of Magnesium oxide?

This question looks at the reaction:

Magnesium + Oxygen goes to Magnesium Oxide

Mg + O -->  MgO

The first step is to calculate the moles of MgO produced using the mass in the question and the relative formula mass of MgO.

The RFM of MgO can be found using a periodic table. The atomic mass of Mg is 24 and the atomic mass of Oxygen is 16. Therefore the RFM of MgO is 24+16=40.

Now we can find the moles of MgO using the formula: moles = mass / RFM

moles MgO = 80 / 40

moles MgO = 2

Looking back to the equation for the reaction:

Mg + O --> MgO

We can see that one unit of Mg goes to produce one unit of MgO.

Therefore to produce 2 moles of MgO, we must use 2 moles of Mg.

Thomas C. 11 Plus Maths tutor, A Level Maths tutor, 13 plus  Maths tu...

9 months ago

Answered by Thomas, a GCSE Chemistry tutor with MyTutor

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


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!”

£36 /hr

Hannah S.

Degree: Medicinal Chemistry and Pharmacology (Masters) - Liverpool University

Subjects offered:Chemistry, English Language+ 3 more

English Language
-Personal Statements-

“I'm currently studying medicinal chemistry and pharmacology at the University of Liverpool as part of an 'integrated masters' course designed to fast track students interested in a chemistry as a profession or continuing study to a PhD...”

£22 /hr

Charlotte C.

Degree: Medicine (Bachelors) - Newcastle University

Subjects offered:Chemistry, Human Biology+ 2 more

Human Biology
-Medical School Preparation-

“About Me: I am a second year medical student studying at Newcastle University. I have always loved and had a passion for science and the human body and I hope I can pass some of that love on through my sessions! I have experience work...”

About the author

Thomas C.

Currently unavailable: for new students

Degree: Natural Sciences (Physical) (Bachelors) - Cambridge University

Subjects offered:Chemistry, Science+ 7 more

Further Mathematics
-Personal Statements-
-Oxbridge Preparation-

“Hi! I`m Tom, a 2nd year Natural Sciences undergraduate at Cambridge University. I am a very positive and empathetic person with a love for the Sciences. I am an experienced tutor in Maths, Physics and Chemistry from GCSE to A level a...”

You may also like...

Posts by Thomas

A 0.20 kg mass is whirled round in a vertical circle on the end of a light string of length 0.90 m. At the top point of the circle the speed of the mass is 8.2 m/s. What is the tension in the string at this point?

Differentiate the function: y = sin(x^2)*ln(5x)

How many moles of Magnesium must react with excess Oxygen to produce 80g of Magnesium oxide?

If a cricket ball of mass 500g is thrown upwards from the ground with an initial velocity of 20 m/s, how high will the ball reach?

Other GCSE Chemistry questions

Why is chlorine more reactive than bromine?

What is a Lewis acid?

What is the difference between a covalent and ionic bond?

Where do electrons go in an atom?

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