Sample Exam 1:

General Knowledge:

1. The prefix “k” represents what numeric value?

2. A substance floats when what conditions are met?

3. Name a metalloid in the 4^th period.

4. Whose experiment confirmed the presence of the neutron?

5. The diameter of a dime is determined to be 1.80, 1.90 and 1.75 cm. If the actual diameter is 1.80 cm, is the data precise, accurate, both, or neither. Explain your answer.

6. If the Arsenate ion is AsO₄^-3, what is the arsenite ion?

7. How many significant figures are there in the following?

a. 1.003 b. 0.0023 c. 2.300(10^-3) d. 20.00

8. How does the empirical formula relate to the empirical formula?

9. How many molecules are there in 1 mole of Na?

10. What quantity relates the moles of HCl to its mass in g?

II. Calculations: Show your set-up, and express your answers to the proper number of sig f igs. All but Temperature units should be shown in scientific notation.

1. 2.55 mg = ? T

2. 1.25(10³)m/s = ? mi/h

3. 22.3 (ft)lb = ? (kg)m

4. 22.55 °C=? °F

5. 22.55 °C=? K

6. 25 lb of Hg (d=13.69g/mL) occupies what volume in L?

III. Classification of matter:

1. Consider the following data for the new element Barclium, Bc, it has the atomic number 126.

It is found to be 35% ¹⁴⁶Bc, 46% ¹⁴⁷Bc, and 19% ¹⁵¹Bc.

a. What is the atomic mass of Barclium?

b. How many protons, neutrons, and electrons are there in it?

c. How many p⁺, n⁰, ane e^- are there in the Bc⁺³ ion?

2. A vial is discovered on the shelf. It is a yellow powder. When it is dissolved in ethyl alcohol, the solution is yellow and a white solid remains. What can be concluded about the powder?

3. A liquid is found oozing out of a lunar rock. It cannot be distilled, and remains unchanged when subjected to electricity. WHAt can be said about the liquid?

Classify the following as pure or mixtures. Once established, under what subheadings do they fall? (Het Mix, Hom. Mix, Element, Compound or Molecule, or Atom)

a. CuO

b. Salt water

c. Milk

4. Complete the following with neutral substances and their names:

	CO3^-2	S^-2	MnO4^-	ClO3^-
Mg^+2
H^+
Fe^+3
Zn^+2

5. Write formulas from the following:

a. Mercury(I)chloride

b. Potassium Chlorate

c. Sulfur Trioxide

d. Acetic acid

e. Sulfurous acid

f. Hydrocyanic acid

g. Ammonia

6. Balance the following reaction:

a. BaO + H₃PO₄ à Ba₃(PO₄)₂ + H₂O_(l)

b. NH₄Cl_(aq) + Hg₂(NO₃)_2(aq) à Hg₂Cl_2(s) + NH₄NO_3(aq)

Consider the following:

For balanced reaction 6a: BaO + H₃PO₄ à Ba₃(PO₄)₂ + H₂O_(l)

a) If you have 2.55 g of BaO: How many moles are there?

How many formula units are there?

How many amu are there

b) How much H₃PO₄ in g are needed to react 2.55 g BaO?

c) If you react 2.55 mol BaO with 3M H₃PO₄, what volume, in mL is needed?

d) If you react 25mL of 3M H₃PO₄ with 2.55 g BaO, what mass of Ba₃(PO₄)₂ will be produced?

How many moles of excess reagent are there?

Consider the following compound. Determine its empirical formula and its molecular formula.

212.0722	Molar Mass
%C	39.64546
%H	60.35454

Also a 10% Rule (Read equipment to the proper precision question)