Chemistry Final Exam Review 2021
Choose the correct name for the compound HClO _3 ..
- Chloric acid
What would be the pH of a solution of a 0.015 M of HCI ?
1.80 ( not on test)
" An acid is a substance that forms hydrogen ions (H^ + ) when dissolved in water . " This is an example of
; an Arrhenius definition
____represents quantitatively the reactants and products in a chemical reaction
A balance Chemical equation
What is the percent of hydrogen in methane , CH 4 ?
Answer , 25.1
Methane (CH 4 ) in water
Answer , insoluble
The mole ratio of the elements in a compound's molecular formula is
Answer , multiple of the mole ratio of the elements in its empirical formula.
What is the molar mass of Al_2O_3
Answer 102 g/mol
What is the molar mass of MgSO 4
Answer 120.37 amu
A sample of 0.0255 mol potassium hydroxide , KOH , was dissolved in water to yield 10.0 mL of solution . What is the molarity of the solution ?
Answer 2.55 M
what are conditions that describe Standard Temperature and Pressure (STP)
Answer 22.4L , OK: 274•C , 1 atm
What would be the pH of solution that has an [H^ + ]concentration of 1 x 10 ^ - 4 l
Answer 4.0
What is the mass of one mole of helium gas ?
Answer 4g ;
What is the new pressure of 150 mL of a gas that is compressed to 50 when the original pressure was 3.0 atm and the temperature is held constant ?
Answer 9.0 atm
In the reaction 2 H 2 +O 2->2 H 2 O how many moles of oxygen are required to fully react with 6.0 mol of hydrogen ?
Answer : 12.0 mol
Which compound has the smallest molar mass?
Answer : ; H2O
A student observes what happens when two different aqueous solutions are mixed in a test tube. Which of the following observations would be most indicative of precipitation reaction?
Answer : a solid settles out
A solution that contains the maximum amount of solubMakete that is soluble at a given temperature is said to be
Answer : saturated ;
Which Coefficients correctly balance the equation below ? CH _4 +O_2 CO_2 +H_2 O
Answer :1,2,1,2
The average kinetic energy of the particles in a sample of matter is measured as the
Answer :; temperature
How many Joules of heat are required to raise 65 grams of water from a temperature of 35 degrees * C to a temperature of 57 degrees * C ? The specific heat of water is 4.18 J/g*^ C
Answer ; 5977.4 J
Which of the following would result in being able to dissolve a greater amount of gas in a solution ?
Answer ; Decrease the pressure of the solution
Which of the following variables are NOT needed to calculate heat ?
Answer ; Time
. If the temperature of a gas changes, but the number of moles and volume remain constant , which of the following values must also change?
Answer Pressure
. Any substance that does not conduct electricity when in solution is called a(n)
Answer electrolyte
Which of the following physical properties does NOT describe an acid ?
Answer feels slippery
What causes surface tension in water ?
Answer hydrogen bonding
When preparing a solution, the substance that is to be dissolved is called
Answer the solute
What coefficients are needed to correctly balance the equation shown ? Mg + HCl -> MgCl_2 + H_2.
Answer, 1211
Nitrogen reacts with hydrogen to form ammonia What is the mole ratio between nitrogen and hydrogen N 2 +H 2 —> NH 3
Answer, 1:3
Calculate the approximate volume of a 1.50 mol sample of gas at 15 ° and a pressure of 3.75 atm (R = 0.0821Latm / mol K)
Answer, 9.46L
Water Boils at ____ degrees CELSIUS
Answer,100
How many grams of NaCl are present in 11.00 moles?
Answer:, 642.8g
How many Mg 2+ ions are present in 3.00 moles of MgCl 2
Answer; 1.81 x 10 ^24
The number of valence electrons in Group 2 elements is
Answer; 2
What process takes place when the average energy of a gas's particles decreases ?
Answer; condensation
. A student wants to identify a 4.78 g unknown metal sample She applies 3.00 Joules of heat to the sample and measures a temperature change from 24.94°C to 28.86 degrees * C Based on the information and the table shown, what is the most likely identity of the metal?
Answer; lead
Stoichiometry is...
Answer;The relationships among the quantities of reactants and products involved in chemical reactions.
During and endothermic reaction , heat content in the surroundings decreases because
Answers; The reaction absorbs heat energy
Which of the following describes the process of sublimation ?
DH 2 O(g) —>H 2 O(s)
Which must be present for a piece of iron to rust
Oxygen
Which of the following is not one of the postulates of the kinetic molecular theory for ideal gases ?
The particles attract and then repel each other .
Water can dissolve many substances because it has
a partial charge on each side of its molecules
Strong acids are those that
dissociate completely , answer , : lose their protons more easily