Which of the following correctly expresses the value of 0.0149 in scientific notation AND in the SI unit

1.49 x 10-2 g/mol

RATIONALE

To convert to scientific notation, place the decimal after the first non-zero number. This yields 1.49. To get the decimal to this location, you moved 2 spots to the right (meaning a negative exponent), so 1.49 x . The SI unit for density is kilogram per cubic meter ().

2.Which of the following is a transition metal?

ans: Mn

Transition metals are located in columns 3-12. The only element listed that is in one of these columns is Mn.

3 .A 200.0 cg block at 55F has a volume of 4.14 cm.

Which answer choice represents BOTH the correct temperature of the block in Kelvin AND the correct density of the block in g/cm?

ans: 286 K; 4.83 x 10 g/cm

Convert F to K by first converting F to C, then adding 273.15. Since d = m/v, both mass and volume are needed (in grams and cubic centimeters, respectively, since that is the desired density unit in the question). Convert cg to g to determine mass.

4 Which of the following is nonpolar and has a tetrahedral molecular geometry?

ans: CH

RATIONALE

Each H surrounds the central C atom, and there are no lone pairs of electrons around the carbon to affect bond angles, so this is tetrahedral. The C-H bonds are polar in the direction of C, thus in the same direction, and thus cancel out, resulting in a nonpolar molecule.

CONCEPT

5Which of these would a chemist most likely study?

matter

RATIONALE

Chemists study the composition, properties, and interaction of matter.

6The chemical formula for nitrosyl fluoride is NOF. In the Lewis structure, N is the central atom.

How many single bonds are in NOF?

ans:1

7.The top speed of a Pontiac GTO 6.0 is 170.26 mph. Given that 1 km = 0.62137 mi and 1 hr = 60 min = 60 s, how fast is this in km/s?

Express your answer using the correct number of significant digits.

0.076113 km/s

RATIONALE

Convert miles to km using the conversion factor 1 km = 0.62137 mi, and convert 1 hour to second by using 1 hr = 60 min = 60 s. So, (170.26 mi/1 hr) x (1 km/0.62137 mi) x (1 hr/60 min) x (1 min/60 s) = 0.0761131. Our significant figures are determined by the 5 significant figures in 170.26 (or 0.62137, since it also has 5), since this is a multiplication/division problem and 5 is the fewest number of significant figures. So when rounded to 5 significant figures, the final answer is 0.076113 km/s.

8Which of the following choices could be an isomer of a compound with an empirical formula of CHO?

CHO

CONCEPT

Introduction to Molecules

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9Which of the following is a property of liquids, but not solids or gases?

forms a slightly curved upper surface when acted upon by gravity

10Which of these pairs of atoms would experience a polar covalent bond?

C and O

RATIONALE

This would be a polar covalent bond, since it is a bond between two nonmetals whose differences in electronegativity values are in the polar covalent range.

11According to Dalton's theory, __________.

atoms are the smallest units of matter

12Accuracy is defined as how close a measured value comes to a _____ value.

ans :true

CONCEPT

Measurement Uncertainty

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13As a wave's frequency increases, its energy ______.

increases

CONCEPT

14Which element has an electron configuration of [Ne]3s3p?

phosphorus

CONCEPT

15

What is the correct name for SF?

disulfur decafluoride

CONCEPT

Nomenclature

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16

How many protons are in a nitrogen atom with a 3- charge?

7

RATIONALE

The number of protons in an element does not change and is not affected by charge. It identifies the element. The number of protons can be determined by the element's atomic number on the periodic table. The atomic number of nitrogen (N), and thus its number of protons, is 7.

CONCEPT

17

The scientific method requires the use of information that is based on observation or experimentation.

This type of information is called which of the following?

ans Empirical evidence

18

Which of the following atoms has the largest atomic radius?

Ba