CHEM 1451 - UTA - General Chemistry

Which of the following would most likely be the uncertainty (or the error) associated with the measurement of 0.0980 g?

+/- 0.0010 g

+/- 0.0001 g

+/- 0.01 g

+/- 0.0100 g

+/- 0.00001 g

+/- 0.0001 g

A patient has 25.0 mL of blood drawn and this volume of blood has a mass of 36.5 g. What is the specific gravity of the blood? (Assume that the density of water is 1.00 g/mL)

6.85

0.146

36.5

0.685

1.46

1.46

Express 21 ug (micrograms) in scientific notation without using metric prefixes...

2.1 * 10^-8 g

2.1 * 10^-5 g

0.21 * 10^-7 g

21 * 10^-7 g

21 * 10^-5 g

2.1 * 10^-5 g

An alloy contains 55 g of silver, 3 g of gold, and 22 g of copper. What is the percentage of silver in the alloy? Round off your answer to the tenths place.

82.1%

0.6%

55.0%

68.8%

73.6%

68.8%

At 20C, if the mass of the unknown is 3.3 g and its volume is 4.2 mL, what is the density of the unknown at 20C?

5.3 g/mL

3.3 g/mL

1.4 g/mL

0.79 g/mL

1.6 g/mL

0.79 g/mL

At 20C, what is the mass in grams of 4.2 mL of isopropyl alcohol? (Density of isopropyl alcohol = 0.785 g/mL)

3.3 g

.14 g

5.3 g

0.19 g

1.6 g

3.3 g

Given the calculation 123.667 - 21.9, what is the correct number of significant figures in the answer? Assume that all numbers in the calculation are measured numbers.

2

1

4

5

3

4

Given the calculation: 0.114 * 5.2344, what is the correct number of significant figures in the answer? Assume that all numbers in the calculation are measured numbers.

3

1

2

5

4

3

Which of the following is the largest number? (Hint: write out each number into standard notation, and then compare them. What do you mean by "largest"? For example, -0.1 is the largest number among -6,

-0.1, and -120).

-1.3 * 10^-1

-5.44 * 10^2

-6.40 * 10^-5

-8.3 * 10^-6

-3.1 * 10^-8

-3.1 * 10^-8

Determine the physical state of hydrogen bromide at -74.1C by using the following data. Assume that pressure is 1 atm.

The melting point of hydrogen bromide = -88.8C

The boiling point of hydrogen bromide = -66.7C

Liquid

Solid

Gas

Liquid

Write 67000 in scientific notation

0.67 * 10^4

0.67 * 10^5

6.7 * 10^4

67 * 10^3

67 * 10^4

6.7 * 10^4

The normal dosage for azinthromycin, an antibiotic, is 3.30 mg/kg. What is the proper dose for a 150 lb. patient? (Given: 1 kg = 2.205 lbs)

224 mg

100. mg

425 mg

300. mg

495 mg

224 mg

Which of the following measurements is/are expressed to 3 significant figures? Select all that apply and only the correct items.

(I) 0.022 m

(II) 320 um

(III) 0.502 L

(IV) 0.088 kg

(I) and (II)

(I) and (IV)

(II) and (III)

(III) and (IV)

(III) only

(III) only

Perform the calculation below. Assume that all numbers were measured. How many significant figures in the result of the calculation?

22.1-1.8 + 101.35

4

3

2

6

5

3

A student measured the mass and the volume of a sample three times. Then the density of the sample was calculated for each measurement and the result was summarized in the table below. Calculate the percent error of the average density of the measurements if the reference value of the density of the sample was 2.71 g/mL. Round your answer to one significant figure.

1 - 2.75 g/mL

2 - 2.73 g/mL

3 - 2.68 g/mL

0.4%

3%

0.2%

9%

7%

0.4%

Perform the following conversion: 24.9 ng into milligrams.

2.49 * 10^-6 mg

2.49 * 10^-4 mg

2.49 * 10^-5 mg

2.49 mg

2.49 * 10^-3 mg

2.49 * 10^-5 mg

Which of the following statements is/are correct? If none of them is correct, then choose "None".

(I) 25C is higher temperature than 283K

(II) 28C is higher temperature than 32F

(I) only

(I) and (II)

(II) only

None

(I) and (II)

Which of the following statements is correct? If none of them are correct, choose "None".

Protons move outside of the nucleus of an atom.

The significant portion of the mass of an atom comes from the mass of electrons.

An atom is electrically neutral because the number of electrons and the number of protons are equal.

The number of neutrons in an atom is always equal to the atomic number of the atom.

None

An atom is electrically neutral because the number of electrons and the number of protons is equal.

Determine the identity of an atom whose period number is 6 and group number is 6B.

Antimony

Mercury

Arsenic

Tungsten

Lead

Tungsten

Determine the number of unpaired electrons present in the Lewis electron-dot structure (or symbol) for chlorine?

0

1

3

7

8

1

Calculate the number of protons (p+), electrons (e-), and neutrons (n0) in one atom of 28Al.

28p+, 13e-, 13n0

13p+, 13e-, 28n0

13p+, 28e-, 15n0

13p+, 13e-, 15n0

13p+, 28e-, 13n0

13p+, 13e-, 15n0

Determine the number of electrons in the second shell (n=2) of one Mg atom.

2

4

6

8

12

8

Choose the response that best described the mass of one nitrogen atom.

7.00 g

14.01 amu

14.01 g/mol

14.01 g

7.00amu

14.01 amu

Arrange the following atoms in increasing order of size (from smallest to largest):

N, Na, F

F < Na < N

F < N < Na

Na < F < N

Na < N < F

N < Na < F

F < N < Na

Specify the number of valence electrons, and the number of the energy level (n) that holds the valence electrons for Se

8 valence electrons and n = 2

4 valence electrons and n = 4

8 valence electrons and n = 6

4 valence electrons and n = 6

6 valence electrons and n = 4

6 valence electrons and n = 4

The density of chloroform is 1.49 g/mL at 20°C. Determine the mass (in grams) of 1.8 mL of chloroform at 20°C.

m=0.002682 

Determine the physical state of carbon tetrachloride, at –11.5°C by using the following data. Assume that pressure is 1 atm. The melting point of carbon tetrachloride= –23.1°C The boiling point of carbon tetrachloride = 76.8°C

At

-11.5°Cnegative 11.5 °C

−11.5°C

and

1 atm1 atm

1 atm

pressure, carbon tetrachloride is in the liquid state.

Determine the number of unpaired electrons present in the Lewis electron-dot structure (or symbol) for iodine?

1

Consider the following three atoms. Ga Kr Rb Arrange them from the smallest to the largest in size.

Ga < Kr < Rb

Determine the physical state of carbon tetrachloride, at –11.5°C by using the following data. Assume that pressure is 1 atm. The melting point of carbon tetrachloride= –23.1°C The boiling point of carbon tetrachloride = 76.8°C

liquid