Chemical systems and us

Question 1

Define acids(Arhenius theory)

Answer 1

Acids are substances that release hydrogen ions when they dissolve in water

Question 2

Define bases(Arhenius theory)

Answer 2

A base is a substance that produces hydroxide ions when dissolved in water

Question 3

Is vinegar an acid or base

Answer 3

Acid(Acetic)

Question 4

Are fertilizers(ammonia) base or acid?

Answer 4

Base

Question 5

Define acid(Bronsted-Lowry theory)

Answer 5

A Bronsted-lowry acid is defined as a proton (hydrogen ion) donor

Question 6

Bronsted-lowry base

Answer 6

A Bronsted-lowry base is defined as a proton (hydrogen ion) acceptor

Question 7

Difference between alkali and base

Answer 7

Alkali dissolve in water.

Question 8

Define dissociation

Answer 8

The splitting of a substance into ions

Question 9

Strong acid

Answer 9

A strong acid is an acid that dissociates almost completely in aqueous solutions

Question 10

Weak acid

Answer 10

A weak acid is an acid that partially (or incompletely) dissociates in aqueous solutions

Question 11

List three indicators

Answer 11

Indicators consist of pH levels, litmus paper, and universal indicators

Question 12

Which indicator is capable differentiating between the strengths of acids and bases?

Answer 12

Universal indicator

Question 13

Define concentration of a substance

Answer 13

The term concentration refers to how much of the substance there is in a given volume of solution

Question 14

Define dilution

Answer 14

Dilution is the addition of solvent, which decreases the concentration of the solute in the solution.

Question 15

Define concentration

Answer 15

Concentration is the removal of solvent, which increases the concentration of the solute in the solution.

Question 16

Neutralization reaction

Answer 16

A neutralization reaction is a chemical reaction between an acid and a base. The reaction of an acid and a base will always produce a salt and water.

Question 17

Is Na+ soluble or insoluble?

Answer 17

Soluble

Question 18

Is silver(Ag+) soluble or insoluble?

Answer 18

Insoluble

Question 19

Which four sulfates are insoluble?

Answer 19

Calcium, barium, lead, silver

Question 20

Which carbonates are soluble?

Answer 20

Sodium, potassium, and ammonium

Question 21

What does human digestive system have?

Answer 21

Alimentary canal, pharynx(throat), stomach, small intestine, large intestine, rectum, anus

Question 22

Four processes of digestive system

Answer 22

Ingestion, digestion, absorption, egestion

Question 23

Define ingestion

Answer 23

the process of taking in food, drink, or other substances into the body, primarily through the mouth and digestive system

Question 24

Define Digestion process chemical changes

Answer 24

Chemical changes involve the action of digestive enzymes and other substances such as hydrochloric acid and bicarbonate.

Question 25

Define Digestion process physical changes

Answer 25

Physical changes involve the mechanical action of the teeth and saliva, the three-layered muscular stomach wall that mixes the stomach contents, peristalsis along the alimentary canal and even bile which helps to expose fat droplets to the enzyme lipase.

Question 26

Define absorption process

Answer 26

The structure of the small intestine is adapted to maximize and facilitate absorption. In the large intestine water gets removed from undigested substances such as fibre and other waste products which form faeces.

Question 27

Define egestion process

Answer 27

Faeces are temporarily stored in the rectum until they are egested in the process of defecation.

Question 28

Oesophagus purpose

Answer 28

transport food and liquids from the mouth to the stomach, facilitating the digestive process

Question 29

Purpose of pancreas

Answer 29

Secretes pancreatic juice containing digestive enzymes such as proteases, amulases, and lipases. Produces bicarbonates to neutralize the acidic pH from the stomach.

Question 30

Rectum purpose

Answer 30

store feces temporarily before they are expelled from the body

Question 31

Large intestine purpose

Answer 31

Peristalsis continues to move the remaining mixture down the large intestine. Water and some ions are absorbed. Undigested food, faeces, becomes solid and gets stored waiting for egestion

Question 32

Small intestine purpose

Answer 32

Food is moved down with the help of peristalsis and mixed with the digestive juices from the pancreas and the wall of the small intestine. Enzymes such as trypsin, lipase, and pancreatic amylase continue to break down the food into small nutrients that are absorbed into the bloodstream with the help of villi.

Question 33

Elements and sugars in carbohydrates

Answer 33

Contain the elements C, H, O Simple sugars such as glucose, fructose, and galactose. Complex sugars(polysaccharides) made up of starch

Question 34

What do fats(lipids) do

Answer 34

Source and storage of energy in the body; insulate the body and vital organs and structures; cell membranes and some hormones are made of fats.

Question 35

Purpose of fiber

Answer 35

Gives a bulky consistency to food to help it move through the digestive system; slows down the absorption of some molecules such as sugars

Question 36

Lipase enzyme

Answer 36

Produced in pancreas, performs functions in small intestine, breaks down fats, producers fatty acids, pH level 7

Question 37

Amaylyse enzyme

Answer 37

Produced in salivary glands, performs function in mouth, breaks down starch(carbs) food, producers maltose, pH level 7

Question 38

What process in the body maintains temperature?

Answer 38

Homeostasis

Question 39

Three components of homeostasis

Answer 39

A receptor detect change inside or outside the body A control centre to process sensory information and coordinate action - central nervous system An effector to direct an appropriate response such as sweating and vasodilation to regulate temperature.

Question 40

What does the hypothalamus do?

Answer 40

Measures the temperature of the blood flowing through it and collects information from temperature sensors around the body. It brings the temperature back to normal(37)

Question 41

What happens in the body during cold condition?

Answer 41

Capillaries constrict(narrow) near the surface of the skin to conserve heat. Sweat secretion stops and hairs stand up trapping an insulating layer of air.

Question 42

What happens in the body during hot conditions

Answer 42

capillaries dilate(widen) near the skin surface to lose heat to the environment. Sweat glands begin to create, causing heat loss by evaporation.

Question 43

What happens when blood sugar is high?

Answer 43

The pancreas responds by releasing insulin. Insulin: Stimulates glucose uptake by tissue cells (muscle, kidney, fat) and the formation of glycogen in the liver (from glucose).

Question 44

What happens when blood sugar is low?

Answer 44

The pancreas responds by releasing glucagon. Glucagon Stimulates the breakdown of glycogen into glucose in the liver. Glucose is released into the blood

Question 45

What does pestle and mortar do

Answer 45

Used to grind up solid chemicals into fine powder and crush solids into smaller pieces