Science - Chemistry Pt.2

Question 1

exceptions in acid

Answer 1

H3PO4 = phosphoric acid
H3PO3 = phosphorous acid
H2SO4 = sulfuric acid
H2SO3 = sulfurious acid

Question 2

factors influencing the rate of chemical reaction

Answer 2

• concentration
• surface area
• temperature
• catalyst
• type of reactant/ nature of reaction
• pressure

Question 3

concentration

Answer 3

greater the concentration, more likely molecules to collide.
* for a solid and pure liquids, their concentrations doesn’t change

Question 4

surface area

Answer 4

heterogeneous reaction (one between matters of different phases), greater contact area between 2 matters, more frequent the collsision

Question 5

temperatuer

Answer 5

greater the temp, higher the average kinetic energy pressed by the reactant molecules.
- energy required to overcome activational energy

Question 6

catalyst

Answer 6

substance which accelerates a chemical reaction

Question 7

pressure

Answer 7

more squished together, closer together

Question 8

other complex compounds

Answer 8

CH4 = methane
CH3CH2OH = ethanol
NH3 = ammonia
NH4 = ammonium

Question 9

acid + metal =>

Answer 9

salt + hydrogen

eg. 2 HCl + Mg > MgCl2 = H2

Question 10

acid + base (neutralisation) =>

Answer 10

salt + water

eg. HCl + NaOH > NaCl + H2O

Question 11

acid + carbonate =>

Answer 11

salt + carbon dioxide + water

eg. H2SO4 + Na2CO3 > Na2SO4 + H2CO3

Question 12

metal + oxygen =>

Answer 12

metal oxide

eg. 2 Fe + O2 > 2 FeO

Question 13

acid + metal oxide =>

Answer 13

salt + water

HCl + NaOH > NaCl + H2O

Question 14

precipitation reaction

Answer 14

occur when cations and anions in aqueous solution combine to form an insoluble ionic solid called a precipitate
(partner swap)
- help determine the presence of various ions in solution.

Question 15

synthesis

Answer 15

combining 2 or more reactants into 1 (or more) products (s)
> more reactants from products
2 H2 + O2 = 2 H2O
A + B = AB

Question 16

decomposition reaction

Answer 16

a single compound breaks apart into two or more elements or compounds (component elements).
- Usually energy is required to make this happen.
- less reactants, mroe products
SO2 = S + O2
AB = A + B

Question 17

valency

Answer 17

8 - how many electrons in the outer shell

Question 18

electron configuration

Answer 18

representation of the arrangement of electrons distributed among the orbital shells and subshells.

Question 19

diatomic molecules

Answer 19

H2 ave N2 o F2 ear O2 f I2 ce Cl2 old B2 eer

have no fear of ice cold beer

Question 20

balanced equations

Answer 20

in order to satisfy the law of conservation of matter, which states that in a closed system matter is neither created nor destroyed.

Question 21

test for oxygen

Answer 21

glowing splint and place it in a sample of gas, if it re-ignites the gas is oxygen.

Question 22

test of carbon dioxode

Answer 22

Light a splint, which is a long, thin strip of wood. Insert the lit splint into the tube with the gas. If carbon dioxide is in the tube, the flame will go out.

-When carbon dioxide is run through lime water, the water turns cloudy. This is because the water is a solution of calcium hydroxide, and when it reacts with carbon dioxide, a solid precipitate of calcium carbonate forms.

Question 23

factors affecting corrosion

Answer 23

• More the reactivity of metal
• Presence of electrolytes (Oxygen) in water
• Presence of in natural water
• rise in temperature
• coated with layers of metals more active
• Humidity

Question 24

factors affecting rusting

Answer 24

-Iron, Oxygen and Water (air moisture) combine
-can be accelerated when Iron is subjected to nature’s minerals, chemicals and temperature fluctuations.
-Any other form of acid
and corrosion stuff

Question 25

energy levels

Answer 25

The electrons surrounding an atom are located in regions around the nucleus called “energy levels”. represents the 3-dimensional space surrounding the nucleus where electrons are most likely to be. -Each energy level is labeled with the quantum number n (n=1, 2, 3,...)

Question 26

combining power of an element

Answer 26

the valency of the element

Question 27

positive ions forms when

Answer 27

Metal atoms lose the electron, or electrons, in their highest energy level and become positively charged ions.

Question 28

Anion

Answer 28

Non-metal atoms gain an electron, or electrons, from another atom to become negatively charged ions.

Question 29

which one wants to lost and which wants to lose electrons

Answer 29

``` metal = wants to lost gas/nonmetal = wants to gain ```

Question 30

base

Answer 30

slippery to touch and solvent in water - potential for accepting rather than releasing hydrogen ions. - accept a hydrogen ion (H+) from another substance

Question 31

acids

Answer 31

form aqueous solutions with a sour taste and solvent in water - defined as a compound (ion/molecule) that gives hydronium ions to another compound