chem quizzes
A 1.26 g sample of He gas has a pressure of 0.123 atm and a volume of 32.6 L. What is the temperature of the sample, in °C?
-118 °C
1 mole of a gas occupies 22.4 L at
0 °C and 1 atm
Consider the following equation: Cu (s) + 2 HBr (aq) ---> CuBr2 (aq) + H2 (g) A 100. mL solution of 0.025 M HBr that completely reacts with copper metal will produce ___ moles of hydrogen gas.
0.0013 moles
Consider the following equation: Zn (s) + 2 HCl (aq) ---> ZnCl2 (aq) + H2 (g) A 50. mL solution of 2.5 M HCl that completely reacts with zinc metal will produce ___ moles of ZnCl2.
0.063moles
A sample of seawater contains 1.3 g of calcium ions in 3,100 kg of solution. What is the calcium ion concentration of this solution in units of ppm?
0.42 ppm Ca2+ ions
If 0.240 mol of methane (CH4) reacts completely with oxygen, what is the final yield of H2O in moles?
0.480 mol
What is the concentration of a solution formed by diluting 25.0 mL of a 3.2 M NaCl solution to 135.0 mL?
0.59 M NaCl
What is the metric relationship between grams and micrograms?
1 g 100 000 ug
When aluminum sulfate reacts with potassium hydroxide to produce aluminum hydroxide and potassium sulfate, the coefficients are:
1, 6, 2, 3
Which of the following measured numbers has three significant figures?
1.01 cm
A 50.0 mL liquid sample has a mass of 50.7 g. The density of the sample is
1.01 g/mL
A 3.0 kg sample of pond water contains 3.6 mg of a pollutant. What is the concentration of this pollutant in ppm?
1.2 ppm
How many H atoms are in 6.022 × 1023 molecules of water?
1.204 × 10^24
3.00 mol of nitrogen dioxide has a mass of ________.
138 g
What is the electron configuration for potassium (atomic number 19)?
1s22s22p63s23p64s1
Calcium has ________ valence electron(s).
2
State the number of significant figures in the following measurement (write in the number, don't spell it out- Ex. write 3, NOT three) 680 000 km
2
Elements in group 2A(2) of the periodic table form ions with a charge of ________
2+
What is the molar concentration of Li+ ions in a 0.750 M solution of Li3PO4?
2.25 M
The density of a solution is 1.18 g/mL, and its volume is 25.0 mL. The mass of the sample is
29.5 g
If 12.0 g of methane (CH4) reacts completely with oxygen, what is the final yield of CO2 in grams?
33.0 g
What is the mass percent oxygen in sodium carbonate?
45.3%
How many grams of chlorine gas are present in a 150. liter cylinder of chlorine held at a pressure of 1.00 atm and 0. °C?
474 g
The correct symbol for the isotope of potassium with 22 neutrons is
49|19 k
A chemist prepares an aqueous solution of sodium hydroxide. The solution contains 120.0 g of NaOH and has a volume of 600 mL. What is the molarity of this solution?
5.0 M
A saline solution used in intravenous drips for patients who cannot take oral fluids contains 0.92% NaCl in water. How many grams of NaCl are contained in 575 mL of this solution? You can assume denisty of 1.00 g/mL.
5.3 g NaCl
If a car travels 23 miles on 1.0 gal of gas, how many liters of gasoline are needed for a 135 mile trip?
5.9 gal
Round off to three significant figures:
58.5
Oxygen has ________ valence electron(s).
6
Pentane (C5H12) reacts with oxygen (gas) to form carbon dioxide and water. What is the coefficient for water in the balanced equation?
6
What is the molar concentration of NH4+ ions in a 3.1 M solution of (NH4)2SO4?
6.2 M
A 12.0 g quantity of methane (CH4) was used to react with oxygen, and the student collected 22.0 g of carbon dioxide. What was the percent yield?
66.9%
Calculate the molar mass of potassium chloride.
74.55 g
The unit of 1 atmosphere used to describe the pressure of a gas is equal to
760 mmHg
Which of the following measurements are NOT equivalent?
84 cm= 8.4 mm
A saline solution used in intravenous drips for patients who cannot take oral fluids contains 0.92% NaCl in water. What volume of the saline solution must be administered to the patient in order to deliver 7.7 g of NaCl? Assume density of 1.00 g/mL.
840 mL of saline solution
The atomic number of fluorine is ________
9
4.00 mol of sodium has a mass of ________.
92.0 g
Which of the following descriptions of a subatomic particle is correct?
A proton has a positive charge and a mass of approximately 1 amu.
Silver chloride has the following formula
AgCl
What element has the electron configuration 1s22s22p63s23p64s23d104p5?
Br
Name the product(s) of the complete combustion of any hydrocarbon.
CO2 + H2O
What is oxidized in this reaction? Ca(s) + H2SO4(aq) → CaSO4(aq) + H2(g)
Ca
What is the reducing agent in this reaction? Ca(s) + H2SO4(aq) → CaSO4(aq) + H2(g)
Ca
Which of these is an ionic compound?
CaCl2
What element has the electron configuration 1s22s22p63s23p5?
Cl
Copper(I) chloride has the following formula
CuCl
Within an energy level, the ___ orbital is the highest in energy.
F
Select the correct symbol for iron
Fe
What unit of temperature is used in gas law calculations?
Kelvin
A sample of a white solid contains 0.212 g of magnesium and 0.140 g oxygen. What is the empirical formula of this compound?
MgO
Which of the following properties is NOT a characteristic of the Group 1A(1) elements (alkali metals)?
Most of them are liquids at room temperature
Identify each of the following as an element, a compound or a mixture
NaCl - compound sugar and water - mixture Cu and Zn - mixture CO - compound Al - element AR - element
What is reduced in this reaction? C2H4(g) + 3O2(g) → 2CO2(g) + 2H2O(g)
O2
What is the oxidizing agent in this reaction? C2H4(g) + 3O2(g) → 2CO2(g) + 2H2O(g)
O2
Carbon is a(n)________ block element
P
What is the symbol of the element in Period 3 and Group 5A(15)?
P
Barium is a(n)________ block element
S
Identify the physical change in the following list
Silver is melted and formed into a candlestick
Which statement is correct?
The s sublevel contains two orbitals and can hold a maximum of 2 electrons.
The abbreviated electron configuration for the sulfur atom is ________
[Ne]3s23p4
In an atom, the nucleus contains ________
all the protons and neutrons
The elements lithium, sodium, and potassium ________
are in the same group
According to the kinetic molecular theory of gases, particles of a gas
are very far apart
Which picture best represents an element?
b.
Which of the following is a chemical change?
burning sugar
The correct name for CS2 is ________
carbon disulfide
A sodium ion is an example of a(n) ________
cation
The reaction of carbon with oxygen to produce carbon monoxide is an example of which class of reaction? 2C(s) + O2(g) → 2CO(g)
combination
What is the classification for this reaction? SO3(g) + H2O(l) → H2SO4(aq)
combination
The correct name for CuSO4 is ________
copper(II) sulfate
The following reaction takes place when an electric current is passed through water. It is an example of a ________ reaction. 2H2O(l) -----> 2H2(g) + O2(g)
decomposition
In Charles's law, the volume of a gas ________ when the ________ decreases.
decreases, temperature
Which is the chemical change in the following list?
digestion of bread
By definition, which of the following cannot be broken down into simpler substances?
element
The phrase "ability to do work" is a definition of
energy
An ionic compound ________
has a net charge of zero
The main interactions between molecules of ammonia, NH3, are
hydrogen bonds
The strongest forces between HF molecules are
hydrogen bonds
The element that has the symbol Pb is ________.
lead
In which of the following is the metric unit paired with its correct abbreviation?
milliliter / mL
What is the name of the compound NO2?
nitrogen dioxide
The mass number of an atom can be calculated from the ________
number of protons plus neutrons
If 16.0 g of methane (CH4) is allowed to react with 32.0 g of oxygen, what is the limiting reactant?
oxygen
Which of the following polyatomic ions has a 3- ionic charge?
phosphate
The energy stored in the chemical bonds of a molecule is
potential energy
A value of 25 °C is a measurement of
temperature
Which of the following is an example of potential energy?
water stored in a reservoir
