SCIN131 Midterm Review Assessment

Midterm Review Assessment
Part 1 of 8 -
4.0/ 4.0 Points

Question 1 of 22
2.0/ 2.0 Points
Which of the following is true about a good hypothesis?

A.It is testable

B.It is repeatable

C.It is falsifiable

D.All of these are good traits for a hypothesis.

Answer Key: D

Feedback: Good. A good hypothesis is always able to proven wrong with subsequent experimentation.

Question 2 of 22
2.0/ 2.0 Points
The atomic theory is attributed to which of the following scientists?

A.John Dalton

B.Albert Einstein

C.Isaac Newton

D.Galileo Galilei

Answer Key: A

Feedback: Good! It was Dalton.

Part 2 of 8 -
6.0/ 6.0 Points

Question 3 of 22
2.0/ 2.0 Points
7.81 × 10-3 written as a decimal is:

A.0.781

B.0.00781

C.7.81

D.0.000781

E.none of the above

Answer Key: B

Feedback: Good. Scientific notation is discussed in section 2.2 of the text.

Question 4 of 22
2.0/ 2.0 Points
The correct scientific notation for the number 0.050210 is:

A.5.0210 × 10-2

B.5.0210 × 10-4

C.5.0210 × 104

D.5.0210 × 102

E.none of the above

Answer Key: A

Feedback: Good. Scientific notation is discussed in section 2.2 of the text.

Question 5 of 22
2.0/ 2.0 Points
3.294 × 105 written in traditional long form is:

A.0.00003294

B.32.9400

C.3,294.00

D.329,400

E.none of the above

Answer Key: D

Feedback: Good. Scientific notation is discussed in section 2.2 of the text.

Part 3 of 8 -
6.0/ 6.0 Points

Question 6 of 22
2.0/ 2.0 Points
Which of these would NOT be considered matter?

A.grape juice

B.salt

C.water vapor

D.energy

E.none of the above

Answer Key: D

Feedback: the characteristics of matter are discussed in chapter 3

Question 7 of 22
2.0/ 2.0 Points
`If I apply 0.0385 kJ of heat to 0.0175 kg of an unkown metal, and I am able to raise its temperature from 27.0 °C to 30.0 °C, what is its specific heat? (Pay attention to units in this problem)

A.0.73 J/g∙°C

B.4.18 J/g∙°C

C.0.15 J/g∙°C

D.1.4 J/g∙°C

E.none of the above

Answer Key: A

Feedback: Good. This is an application of the specific heat equation.

Question 8 of 22
2.0/ 2.0 Points
`A 7.3 g lump of iron at 40 C received 0.495 kJ of heat, which caused its temperature to increase to 55 C. What is the specific heat of iron in J/g∙°C?

A.240.0

B.22.0

C.4.5

D.45.0

E.none of the above

Answer Key: C

Part 4 of 8 -
6.0/ 6.0 Points

Question 9 of 22
2.0/ 2.0 Points
`Which of these can be found in the nucleus?

A.protons and electrons.

B.only protons

C.electrons and neutrons

D.protons, neutrons, and electrons.

E.protons and neutrons.

Answer Key: E

Feedback: See section 4.3

Question 10 of 22
2.0/ 2.0 Points
`If hydrogen forms an ion, what will its charge be?

A.0

B.1+

C.1-

D.2+

E.none of the above

Answer Key: B

Feedback: See the periodic table and section 4.7

Question 11 of 22
2.0/ 2.0 Points
`How would you correctly write the atomic symbol of barium?

A.B

B.Br

C.Bi

D.Ba

E.none of the above

Answer Key: D

Feedback: See the periodic table.

Part 5 of 8 -
6.0/ 6.0 Points

Question 12 of 22
2.0/ 2.0 Points
`If you were to count all the atoms in the formula Cu2(SO4)3, how many would there be?

A.2

B.3

C.7

D.17

E.none of the above

Answer Key: D

Feedback: use formula to count

Question 13 of 22
2.0/ 2.0 Points
`If you were to count the numbers of atoms of each element in NH4F? (NH4)2HPO4, what would the answer be?

A.N = 2, H = 8, P = 1, O = 4

B.N = 1, H = 5, P = 1, O = 4

C.N = 2, H = 5, P = 1, O = 4

D.N = 2, H = 9, P = 1, O = 4

E.none of the above

Answer Key: D

Feedback: use formula to count

Question 14 of 22
2.0/ 2.0 Points
`What would be the proper way to write the formula for hexasulfur nonafluoride?

A.S7F

B.S6F9

C.S7F10

D.S8F6

E.none of the above

Answer Key: B

Feedback: use naming rules

Part 6 of 8 -
6.0/ 6.0 Points

Question 15 of 22
2.0/ 2.0 Points
`Which of the following is true about a compound's empirical formula?

A.it will always be the same as the molecular formula due to the law of conservation

B.it cannot be reduced to a more simple whole number ratio of elements

C.it is based on the ratios of the masses of each atom present

D.it is unique and no two compounds can have the same emprical formula

E.all of these are true

F.none of these are true

Answer Key: B

Feedback: Good. See section 6.8

Question 16 of 22
2.0/ 2.0 Points
`Calculate the molar mass of N4P4O10.

A.170.0 g/mol

B.339.9 g/mol

C.78.05 g/mol

D.18.00 g/mol

E.100.0 g/mol

Answer Key: B

Feedback: Good. See section 6.3

Question 17 of 22
2.0/ 2.0 Points
`Elemental bromine gas can be used to disinfect hot tubs and pools. What would be the mass of one mole of this gas?

A.79.9

B.6.022 × 1023

C.159.81

D.35

E.none of the above

Answer Key: C

Feedback: Good. See section 6.3

Part 7 of 8 -
6.0/ 6.0 Points

Question 18 of 22
2.0/ 2.0 Points
`There are many signs we can observe to tell us if a chemical reaction has taken place. Which of these would NOT be one of those signs?

A.absorption of light

B.absorption of heat

C.release of heat

D.release of light

Answer Key: A

Feedback: Good. See section 7.2

Question 19 of 22
2.0/ 2.0 Points
`If you are balancing the reaction __Ca3N2 + __H2O → __Ca(OH)2 + __NH3 , what number would go in front of NH3?

A.3

B.2

C.6

D.12

E.none of the above

Answer Key: B

Feedback: Good. See section 7.4

Question 20 of 22
2.0/ 2.0 Points
`Which of the following would be the best way to describe an aqueous solution?

A.water that contains a dissolved compound

B.any liquid that contains a dissolved compound

C.an ionic compound containing water dissolved in it.

D.none of the above

Answer Key: A

Feedback: Good. see section 7.5

Part 8 of 8 -
4.0/ 4.0 Points

Question 21 of 22
2.0/ 2.0 Points
`The oxidation of aluminium is a pretty commoon reaction, and happens via the equation Al + 3O2 → 2Al2O3. Which reactant is limiting if you begin with 5.00 grams of Al and 9.50 grams of O2?

A.Al

B.Al2O3

C.O2

D.both Al and O2

E.not enough information

Answer Key: E

Feedback: Good. See section 8.6

Question 22 of 22
2.0/ 2.0 Points
`As much as we would like for it to be the case, we never get all I the product we are supposed to get when we run a real reaction. Suppose you have a theoretical yield of a 50.0 grams of product. However, your actual yield is only 32.0 g. What is your percent yield?

A.1.56%

B.64.0%

C.0.64%

D.32.0%

E.none of the above

Answer Key: B

Feedback: Good. See section 8.6