Chemistry 1120 Final Study

Arrange the following element in order of increasing electronegativity. Potassium, Silicon, Nitrogen

(Least electronegative) Potassium < Silicon < Nitrogen (Most electronegative)

What is the oxidation number of a sulfur atom in Na2SO3?

4+

How is the measurement 50 micrograms stated in Gigagrams and expressed in Scientific notation with the proper number of significant digits?

5 x 10-14 Gg

How much heat is required to raise the temperature of 25.0 grams of water from 32.0 oC to 87.0 oC? Specific Heat (H2O) = 4.184 J/g oC

5.75 x 103 J

How many valence or outermost electrons does a sulfur atom have?

6 valence e-

How is the number 730 000 000 expressed in scientific notation?

7.3 x 108

What is the correct answer to the proper number of significant digits for the following calculation? 45000 ÷ 0.00123 = ??

8.1

What is the sum of the coefficients "a + b + c +d", where a, b,c and d represent the coefficients of the balanced equation? a Mg3N2 (s) + b H2SO4 (aq) → c MgSO4 (aq) + d (NH4)2SO4 (aq)

9

What type of substance is represented by a glass of tea with a uniform composition throughout?

homogeneous mixture

Which of the following would be considered a physical change?

salt dissolving in water

Which of the following polyatomic ions have a two minus, (2-) charge associated with it?

sulfite

The temperature of liquid nitrogen is 77 K. What is this temperature on the Fahrenheit scale?

-321 F

Which measurement below has three significant digits and four decimal places?

0.0405 m

Which subatomic particle(s) is(are) contained in the nucleus of an atom? 1) Neutron 2) Protons 3) Electrons

1 and 2

Which form of radioactive decay is stopped by skin? 1) Alpha particles 2) Beta particles 3) Gamma radiation

1 only

When Silver forms ionic compounds, what charge does it normally assume?

1+

A carpenter must lay a floor that covers 1500 ft2. What is this area in cm2? 1 foot = 12 inches and 1 inch = 2.54 cm

1.4 x 106 cm2

What is the approximate H-N-H bond angle in the molecule NH3?

109

How many gallons are present in 43.7 Liters? (1 gallon = 4 quarts and 1 quart = 0.946 L)

11.5 gallons

Cobalt-60 is a beta emitter and it is used in cancer therapy. The half life of Cobalt-60 is 5.3 years. What percentage of an enriched sample remains after 15.9 years?

12.5%

What is the missing symbol in the following nuclear equation? 23892U + ??? → 24698Cf + 4 10n

12/6C

What mass of platinum occupies a volume of 75.00 cm3. (Density of platinum = 21.45 g/cm3)

1609 g

An Argon-40 isotope has how many protons (p+) and how many neutrons (n)?

18 p+ and 22 n

The intensity of a radiation source at a distance of 5.00 meters is 49.0 units. What would be the expected intensity of this radiation source at a distance of 2.50 meters?

196 units

Mercury-197 undergoes electron capture. What daughter nuclide is formed after Mercury-197 undergoes electron capture?

197/79Au

Which subatomic particles are comparable (almost equal) in mass and contribute most significantly to the mass of an atom? 1) electron 2) proton 3) neutron

2 and 3

What is the charge of the Ni atom in the ionic compound NiSO4?

2+

Two students combined two different volumes of water. The first student measured 25.4 mL of water using a 100.0 mL graduated cylinder and the second student measured 0.15 mL of water using a 50.00 mL burette. What total volume should be reported after taking into account the proper number of significant digits and the convention used for rounding?

25.6 mL

Ionic compounds are formed by a combination of what two types of elements?

A metallic and a nonmetallic element

What is the formula for an ionic compound that is formed by mixing Al3+ cations with CO32- anions?

Al2(CO3)3

What is the systematic name of the compound with a formula of Al2O3?

Aluminum oxide

Which atom from the list below normally forms four covalent bonds when it forms compounds with other elements?

C

Consider the molecule, CF4. What can be stated about the polarity of the C-F bonds and the polarity of this molecule?

CF4 has polar C-F bonds and is a non-polar molecule.

Which polyatomic ion listed below is acetate?

CH3COO1-

Which set of elements would be expected to have nearly identical chemical properties?

Ca, Sr, Ba

Which of the following elements is considered a metal?

Calcium

A chemical property of Hydrogen, H2 is that it reacts with Oxygen, O2 to produce water, H2O (a molecular compound) as shown below. How does each element in the compound H2O attain the same number of electrons as their respective next nearest Noble gas? 2 H2 (g) + O2 (g) → 2 H2O (l)

Each hydrogen atom and the oxygen atom share two electrons.

Anions are formed when neutral atoms do what?

Gain electrons

Which one of the following is the correct Lewis structure for HCN?

H=C=N****

What is the correct systematic name for the compound Fe3(PO4)2 ?

Iron(II) phosphate

Given the table of electronegativity values below, which of the following bonds below would be considered polar covalent? Element Electronegativity Value Si 1.8 Ge 1.8 K 0.8 F 4.0

K-Si

Which of the following compounds is Potassium sulfite?

K2SO3

Which significant region contains the element, Silicon?

Main Group elements

Which of the following compounds is considered an Ionic Compound?

Mg3P2

What metric prefix is associated with 10-6?

Micro

Which of the following molecules is polar? The molecular geometry is indicated in parenthesis.

NH3 (Trigonal Pyramidal)

Which ion listed below obey the octet rule and are considered relatively stable when balanced with an ion of similar charge?

Na1+

Which element from the list below is a Noble Gas?

Neon

What type of Nuclear reaction is illustrated below? 4019K → 4018Ar + 01e

Positron Emission

What is the correct chemical symbol for the element Sulfur?

S

Which of the following is a third period, Alkali Metal?

Sodium

Provided in the table below are two radionuclides and their corresponding half-life periods. Which radionuclide decays the fastest and which isotope is the least stable? Isotope Half-life period Cobalt-60 5.3 years Sodium-24 15 hours

Sodium-24 decays the fastest and is the least stable.

What is the systematic name for the compound with a formula of SCl2?

Sulfur dichloride

What is the electron geometry for the molecule, PF3?

Tetrahedral

The effect of exposure to radiation is influenced by what factor(s) shown below?

The duration in which the tissue is exposed. The type of radiation and the penetration ability of the radiation. The intensity of the radiation and the distance from the source. The type of tissue that is being exposed.

What is the molecular geometry for PF3?

Trigonal Pyramidal

Listed below are properties of water. Which from the list are physical properties?

Water's melting Point = 0.00 oC.

Consider the molecule, CO2. How many charge clouds (regions of electron density) surround the central carbon atom?

two