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The mass of a balloon is 0.02g before it is filled with air. After it is blown up with air the mass is 0.04g. Assuming oxygen makes up 21% of air, calculate the number of moles of oxygen in the balloon.

After the balloon has been blown up with air it increased its size by 0.02 g (Final mass - initial mass = mass of the air).We are told that of oxygen takes up 21% of air. Therefore, we need to work out 21...

Answered by Greta S. • Chemistry tutor

2883 Views

How do you factorise a quadratic equation where the coefficient of x^2 isn't 1?

For this, we need to use the formula ax²+bx+c. Multiply the coefficient of a from your equation with the value of c. This gives you a value from which you need to find 2 factors of this value w...

Answered by Rosie G. • Maths tutor

6221 Views

What is the problem of evil?

According to many passages in the Bible, God is said to be omnibenevolent (all-loving), omnipotent (all-powerful) and omniscient (all-knowing). Evidence of evil in our world is abundant, with moral evil t...

Answered by Katharine S. • Religious Studies tutor

2187 Views

Describe the bonding in sodium chloride

Sodium chloride is an ionic compound formed by the strong ionic attractions between positively charged sodium ions (which have lost one electron) and negatively charged chloride ions (which have gained an...

Answered by Matthew F. • Chemistry tutor

3958 Views

How do you factorise a quadratic equation where the coefficient of x² isn't 1?

Using the formula ax²+bx+c, multiply the value of coefficient a, from your equation, with the value of c. Next, try to think of two factors of the number you just calculated, which also add tog...

Answered by Grace R. • Maths tutor

3340 Views