Science - Chemistry Pt.1

Question 1

covalent prefixes

Answer 1

1. mono
2. di
3. tri
4. tetra
5. penta
6. hexa
7. hepta
8. octa
9. nona
10. deca

Question 2

acid + metal =

Answer 2

salt + hydrogen gas

Question 3

acid + carbonate =

Answer 3

salt + carbon dioxide gas

Question 4

acid + base (neutralisation, akalii) =

Answer 4

salt + water

Question 5

combustion

Answer 5

burning of a fuel in oxygen to produce energy (oxident, fuel, ignition)

Question 6

combustion equation

Answer 6

CH4 +O2 -> CO2 + H2O

Feul + Oz -> Co2 + H2O + energy

Question 7

complete combustion

Answer 7

fuel totally burns the oxident and fuel is usually hydrocarbon (compound made of H&C)

Question 8

incomplete combustion

Answer 8

not enough oxygen to react with the fuel. other harmful products can be formed other than CO2 or H2O

Question 9

electron configuration

Answer 9

istribution of electrons of an atom or molecule (or other physical structure) in atomic or molecular orbitals.

Question 10

ionic bonds

Answer 10

atoms can either transfer or share their valence electrons.

• chemical bond that generates two oppositely charged ions
• metal loses electrons to become a positively charged cation, whereas the nonmetal accepts those electrons to become a negatively charged anion.

Question 11

covalent bonds

Answer 11

• sharing of a pair of valence electrons by two atoms.
• lead to stable molecules if they share electrons in such a way as to create a noble gas configuration for each atom.
• share electrons in order to achieve octet configuration and become more stable.

Question 12

mass number

Answer 12

number of protons and neutrons in an atom, and it tells us about the mass of the atom in amu,

Question 13

atomic number

Answer 13

atomic number is the number of protons that resides in the nucleus
mass number is the number of protons and neutrons combined.

Question 14

atomic weight

Answer 14

the average weight of an atom of an element

Question 15

molecular weight

Answer 15

the mass of one molecule of a substance

mass of one mole of a substance

Question 16

independent variable

Answer 16

variable that is changed

Time is the independent variable - x axis

Question 17

mole

Answer 17

amount of a chemical substance that contains as many elementary entities as there are atoms in exactly 12 grams of carbon-12

Question 18

calculating atomic weight

Answer 18

atomic mass of element/12 x 12

eg. zn 65/12 x 12 = 65g

Question 19

calculating molecular weight

Answer 19

combined mass of atoms measured in grams

eg. 2) H2SO4 = 2H + S +4O

Question 20

acid

Answer 20

compound in which one or more H+ ions are bonded to a negative ion
- name of acid is based on the name of the negative ion that is part of the acid

Question 21

polyatomic ions

Answer 21

carbonate : CO3 (2-)

nitrate: NO3 (-1)
nitrite: NO2 (-1)
phosphate: PO4 (3-)
phosphite: PO3 (3-)
sulfate: SO4 (2-)
sulfite: SO3 (2-)

Question 22

polyatomic ions

Answer 22

carbonate : CO3 (2-)

nitrate: NO3 (-1)
nitrite: NO2 (-1)
phosphate: PO4 (3-)
phosphite: PO3 (3-)
sulfate: SO4 (2-)
sulfite: SO3 (2-)
hypochlorite: ClO (-1)
chromite: CrO3 (-1)

Question 23

polyatomic ions

Answer 23

carbonate : CO3 (2-)

nitrate: NO3 (-1)
nitrite: NO2 (-1)
phosphate: PO4 (3-)
phosphite: PO3 (3-)
sulfate: SO4 (2-)
sulfite: SO3 (2-)
hypochlorite: ClO (-1)
chromite: CrO3 (-1)

Question 24

compounds

Answer 24

formed when 2 or more elements are combined in fixed amounts

• can be made for their elements (synthesis)
• broken down into their elements (decomposition)

Question 25

molecules

Answer 25

contain 2 or more atoms held together by chemical bonds

Question 26

mixtures

Answer 26

impure substances - 2 or more different types of particles that can be separated using physical separation as not chemically bound

Question 27

pure substances

Answer 27

contain only 1 type of particle (all identical), cant be separated into simpler substances using physical techniques

Question 28

element

Answer 28

simplest type of substance, with only 1 type of atom

Question 29

neutralisation

Answer 29

chemical reaction which an acid and a base react quantitatively with each other
-»> salt and water are mainly the products

Question 30

pH scale

Answer 30

number scale (no unit) to indicate degree of acidity/alkalinity of a substance
acidic solution: 0-6
basic: 7
neutral solution: 8-14

Question 31

active and inactive metals

Answer 31

active: react strongly with other substances
inactive: react weakly ‘’

Question 32

test to see if hydrogen gas

Answer 32

pop test

Question 33

bases

Answer 33

substances that can accept hydrogen ions from another substance other than releasing them (acid)
eg. zinc hydroxide, sodium hydroxide, calcium hydroxide

Question 34

chemical indicator

Answer 34

visible sign when certain molecules are present (presence of an acid base)

Question 35

complex compounds

Answer 35

OH - hyroxide (1-)
SO4 - sulphate
CO3 - carbonate
NO3 - nitrate
CH3COO - acetate (1-)

Question 36

naming metal and non metals

Answer 36

metal first, ‘-ide’
eg. chloride
acid: hydro ___ ic acid
hydrochloride acid (HCl)

if oxgen, ‘-ite-
eg. NO2 (1-)= nitrite
acid: -ous acid
nitrous acid (HNO2)

Question 37

naming non metals

Answer 37

first non metal, prefix for other

name ends in ‘-ide’

Question 38

naming metals and complex compounds

Answer 38

metal and complex compound

Question 39

naming ate ions

Answer 39

-ic
eg. nitrate
= nitric acid (HNO3)

Question 40

dependent variables

Answer 40

variable being tested and measured

speed is the dependent variable. - y axis