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Chemistry

A Level

How do buffers work?

What is a buffer?

A buffer is a solution that resists a change in pH when small amounts of acid or base are added. It is composed of either a weak acid or a weak base wit...

Answered by Daisy D. • Chemistry tutor

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Calculate the percentage, by mass, of carbon in cyclohexane. Give your answer to two significant figures.

formua of cyclohexane C₆H₁₂

molar ratio is 1:2 (divide 6 and 12 by 6 )

to get mass ratio multiply by molar mass (1 x 12 and 2x1)

12:2

Answered by Tom F. • Chemistry tutor

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You added 75cm^3 of 0.5moldm^-3 HCl to impure MgCO2, and some was left unreacted. The unreacted HCl reacted completely with 21.6cm^m of 0.5moldm^-3 NaOH. So what is the percentage purity of the MgCO3 sample?

MgCO₃ +2HCl --> MgCl₂ + H₂O +CO₂

For this kind of question, I would always try to convert what I can into moles because tha...

Answered by Febi S. • Chemistry tutor

7093 Views

What is the effect of a catalyst in an equilibrium process?

A catalyst provides an alternative pathway for a reaction to take place and therefore helping the reaction to take place at a lower activation energy. In an equilibrium process, a catalyst has no effect o...

Answered by Rajenth N. • Chemistry tutor

17557 Views