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Chemistry 211 Key 1 Fall 2007
- The prefix "kilo-" in kilogram means
a) the mass is in millionths (10-^6 ) of a gram. b) the mass is in thousandths (10-^3 ) of a gram. c) the mass is in hundreths (10-^2 ) of a gram. d) the mass is in hundreds (10^2 ) of grams. e) the mass is in thousands (10^3 ) of grams.
- Which of the following statements is false?
a) Elements are substances that cannot be decomposed into simpler substances. b) Precision refers to how closely individual measurements agree with the correct value. c) Numbers obtained by measurement are always inexact. d) Mixtures are combinations of two or more substances, each of which retains its own chemical identity. e) Matter is anything that has mass and occupies space.
- A block has a temperature of 701 ºC. What is its temperature in Kelvins?
a) 372 b) 628 c) 701 d) 974 e) 1290
- _____ is the atomic symbol for potassium.
a) K b) Na c) P d) Po e) none of these
- Elements of Group IIA are called the
a) alkali metals c) chalcogens e) noble gases b) alkaline earth metals d) halogens
- The correct number of protons, neutrons, and electrons in Pt2+^ (Pt-195) is :
a) 78p, 117n, 76e c) 78p, 117n, 78e e) 80p, 115n, 78e b) 80p, 115n, 78e d) 80p, 117n, 78e
- Which of the following ions would you expect not to form?
a) F-^ b) S^2 -^ c) P^3 -^ d) Ca3+^ e) K+
- Which of the following is an example of a combustion reaction?
a) N 2 + 3 H 2 → 2 NH 3 d) C 3 H 8 + 5 O 2 → 3 CO 2 + 4 H 2 O b) 4 Fe + 3 O 2 → 2 Fe 2 O 3 e) CaCO 3 → CaO + CO 2 c) AgNO 3 + NaCl → AgCl + NaNO 3
- Define:
chemistry – the study of the properties of materials and the changes that materials undergo
weight – the force that gravity exerts on an object
physical property – properties that don’t change the identity of the material when measured
anion – negatively charged ions
isotope – atoms of the same element possessing differing numbers of neutrons
theoretical yield – the amount of product expected based on stoichiometry
- Circle the word that will correctly complete the following sentences: (5 points)
Corrosion of aluminum metal is a chemical process. [Problem 1.19a]
Melting of ice is a physical process. [Problem 1.19b]
Pulverizing aspirin is a physical process. [Problem 1.19c]
The mass of a 32 ounce can of coffee is an inexact number. [Problem 1.36a]
The number of students in a chemistry classroom is an exact number. [Problem 1.36b]
- For the following give the name or formula where appropriate: (12 points)
Co(NO 3 ) 2 – cobalt(II) nitrate [Practice exercise 2.12c]
ammonium sulfate – (NH 4 ) 2 SO 4 [Problem 2.59j]
NO 2 – nitrogen dioxide [Problem 2.66c]
hydrobromic acid – HBr(aq) [Problem 2.64a]
- Complete the following: (10 points)
CH4 (g) + 4 Cl 2 (g) → CCl 4 (l) + 4 HCl(g) [Problem 3.11c]
Aqueous calcium hydroxide reacts with phosphoric acid to form solid calcium phosphate and water.
3 Ca(OH) 2 (aq) + 2 H 3 PO 4 (aq) → Ca 3 (PO 4 ) 2 (s) + 6 H 2 O [Problem 3.12e]
