yearly year 10 chemical cauldron

Question 1

what is the law of conservation of mass

Answer 1

Mass in an isolated system is neither created nor destroyed

Question 2

how does the law of conservation of mass relate to chemical reactions

Answer 2

during a chemical reaction things get bigger and smaller but mass is never destroyed or created.

Question 3

what are reactants

Answer 3

they are substances that are used in a chemical reaction

Question 4

what are products

Answer 4

products are the end result of a chemical reaction

Question 5

what is valency

Answer 5

a measure of its combining power with other atoms when it forms chemical compounds or molecules.

Question 6

what is an ionic bond

Answer 6

the metal loses electrons to become a positively charged cation, whereas the nonmetal accepts those electrons to become a negatively charged anion.

Question 7

what is a covalent bond

Answer 7

haring of electron pairs between atoms two have full valency shells

Question 8

what is a metallic bond

Answer 8

force that holds atoms together in a metallic substance.

Question 9

give an example of ionic bonds

Answer 9

NACL

NA loses one electron whereas CL gains an electron

Question 10

what is an example of covalent bonding

Answer 10

H20 share electrons to become stable

Question 11

what is an example of a metallic bond (4)

Answer 11

Cu, Al, Au, Ag

Question 12

what is precipitation

Answer 12

is the emergence of a insoluble solid in a liquid

Question 13

what is the importance of the activity series

Answer 13

By using the reactivity series of metals, one can predict the products of displacement reaction.

Question 14

give an example of the effect of the activity series of metals

Answer 14

magnesium metal can displace zinc ions in a solution.

Question 15

what is the metal displacement reaction

Answer 15

Displacement reaction is a chemical reaction in which a more reactive element displaces a less reactive element from its compound.

Question 16

give an example of the displacement reaction

Answer 16

Reaction of iron nails with copper sulphate solution

Question 17

what is a combustion reaction

Answer 17

an burning reaction in which something reacts with oxygen.

Question 18

what is neutralisation

Answer 18

a type of chemical reaction in which a strong acid and strong base react with each other to form water and salt.

Question 19

give an example of neutralisation

Answer 19

HCl + NaOH ->NaCl + H20

Question 20

Properties of Acids (4)

Answer 20

turn blue litmus red
taste sour
acids corrode metals
Positively charged hyrdogen ions (H+)

Question 21

properties of Bases

Answer 21

turn red litmus blue
taste bitter
negatively charged hydroxide ions ( OH-)
feel slippery
strong bases are caustic

Question 22

what happens when metals react to acids

Answer 22

Acids react with most metals to form a salt and hydrogen gas

Question 23

what happens in a reaction between acids and carbonates

Answer 23

salt, water and carbon dioxide gas are formed.