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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!...

Answered by Thomas C. • Chemistry tutor

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Calculate the pH of the buffer solution resulting from mixing 250 cm^3 of 0.3 moldm^-3 ethanoic acid with 250cm^3 of 0.2 moldm^-3 sodium hydroxide. The Ka of ethanoic acid is 1.8 x 10^-5.

As an acid is being added to a base, you first need to calculate what is left after they react. Without doing any calculations, we can already see that the acid is in excess as both solutions have the sam...

Answered by Tutor125302 D. • Chemistry tutor

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What is a mole?

A mole is a measure of quantity, such that when you have a mole of something, you have 6.02 x 10²³ atoms/molecules of it. The number of atoms/molecules in a mole is called "Avogadro's Numb...

Answered by Amy F. • Chemistry tutor

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What characteristic ion can denote the difference between an acid and an alkali and give an example?

For an acid the formation of a hydrogen ion denotes it as being acidic.HCL -> H+ + CL-Where as for an alkali the formation of a hydroxyl ion denotes is as being alkaliNAOH -> Na+ and OH-

Answered by Scarlett K. • Chemistry tutor

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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...

Answered by Abigail J. • Chemistry tutor

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