Chapter 1 definitions

Question 1

amount of substance

Answer 1

the amount of substance in the quantity that has moles as its unit, chemists use it as a way of counting atoms

Question 2

mole

Answer 2

a mole is the amount of any substance containing as many particles as there are carbon atoms in exactly 12g of the carbon-12 isotope

Question 3

Avogadro constant

Answer 3

the Avogadro constant is the number of atoms per mole of the carbon-12 isotope

Question 4

molar mass

Answer 4

is the mass per mole of a substance the units of molar mass are gmol-1

Question 5

empirical formula

Answer 5

an empirical formula is the simplest way of showing a chemical formula, it shows the ratio between elements rather than actual number of atoms of each element

Question 6

molar gas volume

Answer 6

is the volume per mole of a gas, the units of molar volume are dm3mol-1 at room temperature and pressure, the molar volume is approximately 24.0 dm3mol-1

Question 7

concentration

Answer 7

the concentration of a solution is the amount of solute, in mol, dissolved per 1dm (1000cm ) of solution

Question 8

standard solution

Answer 8

a standard solution is a solution of known concentration. Standard solutions are normally used in titrations to determine unknown information about another substance

Question 9

hydrated

Answer 9

refers to a crystalline compound containing water molecules

Question 10

anhydrous

Answer 10

refers to a substance that contains no water molecules

Question 11

water of crystallisation

Answer 11

refers to water molecules that form an essential part of the crystalline structure of a compound.

Question 12

What is an acid

Answer 12

A proton donor

Question 13

What is a base

Answer 13

An proton acceptor

Question 14

What is an alkali

Answer 14

A soluble base realeasing OH- ions

Question 15

relative isotopic mass

Answer 15

the mass of an atom of an isotope compared with 1/12 of the mass of an atom of carbon-12

Question 16

relative atomic mass

Answer 16

the weighted mean mass of an atom of an element compared with 1/12 of the mass of an atom of carbon-12

Question 17

REACTIONS WITH ACIDS EQUATIONS

Answer 17

Acid(aq) + metal carbonate(s) = carbon dioxide(g) + water(l) + salt(aq)
Acid(aq) + metal oxide(s) = Salt (aq) + water (l)
Acid(aq) + alkalis(aq) = salt(aq) + water
Acid (aq) + metal(s) = salt(s) + hydrogen (gas)