Chemical reactions and quantities

Question 1

chemical reactions

Answer 1

involves the change of the bonding between atoms in the reactants in forming the products

Question 2

chemical change

Answer 2

occurs when a substrate is converted into one or more substances with different formulas and different properties

Question 3

signs that a chemical reaction is taking place

Answer 3

formation of bubbles
change in color
production of a solid
heat is produced/absorbed

Question 4

heterogenous situation

Answer 4

different states

Question 5

combination reaction

Answer 5

2 or more elements form one product

Question 6

decomposition reaction

Answer 6

one substance splits into 2 or more simpler products

Question 7

single replacement reaction

Answer 7

one element takes the place of a different element in another reacting compound

Question 8

double replacement reaction

Answer 8

the positive ions in the reactant compounds switch places

Question 9

combustion reaction

Answer 9

a carbon-containing compound burns in oxygen gas to form carbon dioxide and water. energy is released as a product in the form of heat

Question 10

toxicity of CO

Answer 10

• carbon monoxide is a colorless, odorless, poisonous gas
• attaches to hemoglobin molecules when inhaled
• reduces the amount of oxygen that can reach the cells
• causes a person to experience a reduction in exercise capability, visual perception and manual dexterity

Question 11

hemoglobin

Answer 11

protein in the blood that transports oxygen to cells

Question 12

what happens when hemoglobin bound to CO reaches 10%?

Answer 12

a person may experience shortness of breath, mild headache, and drowsiness

Question 13

what happens when hemoglobin bound to CO reaches 30%?

Answer 13

a person may experience more severe symptoms, including dizziness, mental confusion, severe headaches, and nausea

Question 14

what happens when hemoglobin bound to CO reaches 50%?

Answer 14

a person could become unconscious and die if not treated immediately with oxygen

Question 15

redox of FAD

Answer 15

FAD can be reduced to FADH2 by the transfer of 2 hydrogen atoms: necessary for the production of energy

Question 16

oxidation

Answer 16

addition of oxygen
loss of hydrogen and electrons

Question 17

reduction

Answer 17

loss of oxygen
gain of hydrogen and electrons

Question 18

oxidation of ethanol

Answer 18

ethanol gets oxidised by an enzyme called alcohol dehydrogenase to a compound called acetic aldehyde which is more toxic than ethanol itself. to reduce the toxicity in our liver, the acetic aldehyde is further oxidized to acetic acid

Question 19

approach to take when balancing redox equations

Answer 19

1. identify the elements that undergo oxidation and reduction
2. write the two semi-reactions. use OH- and H+ and H2O
3. multiple the coefficients that make both semi-reactions use the same number of electrons
4. add the two together

Question 20

molar mass

Answer 20

the mass of 1 mole of an element expressed in grams

Question 21

law of conservation of mass

Answer 21

it indicates:
1. matter cannot be created or destroyed
2. no change in total mass occurs
3. the mass of products= mass of reactants

Question 22

limiting reactant

Answer 22

the substance that is used up first, limits the amount of product that can form

Question 23

excess reactant

Answer 23

the reactant that does not completely react and is left over at the end of the reaction

Question 24

theoretical yield

Answer 24

the maximum amount of product

Question 25

actual yield

Answer 25

amount of product obtained

Question 26

percent yield

Answer 26

ratio fo actual yield to theoretical yield actual yield/ theoretical yield x 100%