CHEMISTRY - CHALLENGE 5 QUIZ

CHEMISTRY

CHALLENGE 5 QUIZ

Acids & Bases, pH

In Chemistry we can measure the acidity or alkalinity of any substance with use of a pH scale.

Multiple Choice

What is the total range of values in this scale?

• 1-16

• 0-20

• 0-7

• 7-14

• 0-14

Acids & Bases, pH

An acid is any substance containing hydrogen that has the capacity of donating a hydrogen ion to any other substance.

Open Ended

What is the range of values from the pH scale that determine if a substance is acidic?

Multiple Select

What are some of the properties of these substances? (Check all that apply)

• Sour taste

• Corrosive

• Bitter Taste

• Highly reactive with metals

• Slippery on touch

Acids & Bases, pH

A base or alkaline substance is any substance that when present in an aqueous solution, releases hydroxyl ions (OH-) into the medium.

Multiple Choice

A substance with a pH value of 7.0 is considered a base.

• True

• False

Open Ended

What is the range of values from the pH scale that determine if a substance is alkaline?

Multiple Choice

Combining an acid and a base will give as a result a salt.

• True

• False

Multiple Choice

What is the pH value of water?

• 5

• 6.5

• 8

• 7

• 10

Open Ended

Is water considered an acidic or an alkaline substance? If you think otherwise, explain:

Multiple Choice

The healthy pH values for blood are:

• 6.8 - 7

• 7.5 - 8

• 7.3 - 7.4

• 8.0 - 8.4

Multiple Choice

If our blood pH levels decrease severly from the healthy range we can suffer many health problems, including death. This condition is called:

• Alkalosis

• Acidosis

• Hemolysis

• Cancer

• Anemia

Multiple Choice

Many skin conditions are caused by an imbalance in the pH levels of the skin.

• True

• False

Oxidative Stress, Free Radicals & Antioxidants

Oxidation refers to the process where Oxygen atomsare added to a substance and take electrons away from it.

Multiple Choice

Oxidative Stress occurs in cells at all times

• True

• False

Multiple Choice

Name of the molecules responsible for causing Oxidative Stress

• Free Radicals

• Antioxidants

• Reducing Agent

• Bases

• Acids

Fill in the Blank

The molecules mentioned in the previous question steal ____ from other molecules present, thus, creating more of them that eventually will trigger a chain reaction.

Multiple Select

Select the characteristics that apply to these molecules:

• Unstable

• Unpaired e^-

• Stable

• Complete Valence Shell

• High Oxidation numbers

Open Ended

What is the name of a natural antioxidant produced in our bodies and that is also considered the most potent one synthezised by our cells?

Open Ended

Name at least 3 causes of Free Radical formation:

Oxidation & Reduction

Fill in the Blank

When any given atom is losing electrons we can say that it is being

Multiple Choice

When any given atom is being reduced the oxidation number also changes. What type of change will it suffer?

• The oxidation number decreases because electrons are lost

• The oxidation number increases because electrons are gained

• The oxidation number increases because electrons are lost

• The oxidation number decreases because electrons are gained

Multiple Choice

Calcium (Ca) is an Alkaline Earth Metal, which means that it is present in the second group of the Periodic Table. Accoding to the rules reviewed in class for assigning Oxidation Numbers, what will the oxidation number for this element be?

• +2

• -2

• +1

• -1

• None