Top answers

Chemistry
A Level

A sample of CaCO3 has been weighed in at 6.3 g. How many moles of calcium carbonate are present?

The first thing to think of here is what does a mole actually mean?Using the equation: Moles = Mass (g) / Molar Mass we can first find out what the molar mass of CaCO3 is.TO THE PERIODIC TABLE!...

TC
Answered by Thomas C. Chemistry tutor
14198 Views

What is the standard enthalpy change of formation and how does it differ from the standard enthalpy change of reaction?

The enthalpy change of formation is the enthalpy change when 1 mole of a compound is formed from its constituent elements in their standard states. Meanwhile the enthalpy change of reaction is the enthalp...

AJ
Answered by Abigail J. Chemistry tutor
2874 Views

What is a standard electrode potential?

The EMF voltage produced when a half cell is connected to a standard hydrogen half cell under standard conditions. Standard conditions are 298 Kelvin, 100 kPa, and all solutions must be in 1 moldm-3 ...

AJ
Answered by Abigail J. Chemistry tutor
2018 Views

How do you make a buffer?

A buffer is a mix of an excess of weak acid and its salt. Buffers can be made in two ways- by mixing the weak acid with its salt or by partially neutralising the weak acid with base. 1- Making buffers by ...

AJ
Answered by Abigail J. Chemistry tutor
2422 Views

why does silicon dioxide have such a high melting/boiling point?

It has a giant lattice structure, strong covalent bonds are difficult to break etc.

KD
Answered by Kian D. Chemistry tutor
4536 Views

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