Chem Final MC
The charge of tin in Sn(SO4)2 is _____ if sulfate is a -2 charge.
+4
Which of the following measurements have 3 significant figures?
0.0100 L
The molar mass of Na`2 CO`3 is
106.0 g/mol
A 1.0 gram sample of solid iodine is placed in a tube and the tube is sealed after all of the air is removed. The tube and the solid iodine together weigh 27.0 grams. The tube is then heated until all of the iodine evaporates, filling the tube with iodine gas. After heating, the total weight will be _____.
27.0 g
Which of the following would represent .5 mol of gold atoms?
3.011 x 10`23 atoms
A sample of a compound contains 4 g of element A and 10 g of element B. Another sample of the same compound contains 12 g of element A. How many grams of element B would you expect to find in the second sample?
30
2.43 g of magnesium reacts with 1.60 g of oxygen when forming the compound magnesium oxide. If calcium reacts with oxygen in the same atom ratio, how many grams of calcium will react with 1.60 g of oxygen?
4.01 g
Which of the following materials should have the lowest density under normal conditions?
A balloon filled with helium gas
A sample of water is brought to a boil. Which of the following is true while the water is boiling? Which of the following best describes your reasoning for your answer to the previous question?
All of the energy added is used to overcome attractions between the water particles instead of moving them faster
When you ripped the tapes apart in the Sticky Tape Lab, the top and bottom pieces of tape were attracted to each other. Which of the following statement is NOT directly supported by the observations you made in the lab?
Atoms contain smaller particles that carry an electric charge
Which of the following substances would you expect to conduct electricity?
Bleach (sodium hypochlorite, NaOCl, dissolved in water) ~ Metal + Non-Metal
If a compound is 25% hydrogen by mass which of the following compounds could be the chemical formula of the compound?
CH`4
If a compound has an actual molar mass that is 5 times greater than the molar mass of CH`4, which of the following could be the molecular formula?
C`5 H`20
Which of the following would be most likely to be a liquid at room temperature?
C`7 H`8
Numbers placed in front of formulas in a chemical equation are called
Coefficients
Electrolysis can be used to separate this class of substances into simpler materials
Compounds
This class of substances consists of two or more elements in a definite mass ratio
Compounds
Which of the following is a property that can be used to identify the substance?
Density
This class of substances cannot be broken down by physical or chemical means
Elements
When a sample of gas is heated, the motion of the particles Which of the following best explains the reasoning for your answer to the previous question?
Heating transfers energy to the particles that makes them move faster
Which of the following materials should have the highest melting point? Which of the following is the best reason for your answer in the previous question?
Metals and Nonmetals form strong attractions between them in a compound
Which of the following would be reasonable evidence that metals have a positive charge in compounds?
Metals form at the negative electrode during electrolysis of a compound
Alize needs to determine the volume of a container to use in a lab investigation. Which of the following units would Alize NOT use to express his volume measurements?
Milligram
This class of substances can be either characterized as homogeneous or heterogeneous
Mixture
The composition of theses substances can be variable; its physical properties depend on the composition of the material
Mixtures
Which of the following materials should have the highest melting point?
NaF
A rectangular piece of metal is hammered into a thin sheet. Which of the following statements is true about the sheet of metal after being formed into the thin sheet? Which of the following statements best explains your answer to the previous question?
No material was removed from the material during the process so that the volume and mass remain the same.
Which of the following would expand or contract less due to changes in temperature? Which of the following best explains the reasoning for your answer in question?
Particles of solids are too densely packed
New substances formed during a chemical reaction are called
Products
A student places a match on a balance and then lights the match. As the match burns, the mass reading on the scale begins to decrease. Which of the following is the best possibility for what is happening as the match burns?
Some of the matter that was in the match was lost to the surroundings of the system
Which of the following is a property that can be used to identify the substance? Which of the following is the best reason for your answer to the previous question?
The amount of matter in an object can be observed without using a measuring device
A sample of a compound contains 4 g of element A and 10 g of element B. Another sample of the same compound contains 12 g of element A. How many grams of element B would you expect to find in the second sample? Which of the following provides the best justification for your answer to the previous question?
The amounts of each element that make up a compound have set proportions that must always be followed for that compound
You have a bucket of water 25 C and a bathtub filled with water at 25 C. Which of the following statements would be true?
The bathtub contains more energy than the bucket
You have a bucket of water 25 C and a bathtub filled with water at 25 C. Which of the following statements would be true? Which of the following best describes your reasoning for your answer to the previous question?
The bathtub contains more water than the bucket
You have a bucket filled with water at 25 C and a bathtub filled with water at 25 C. Which of the following statements would be true?
The bucket would feel warmer to touch
Which of the following materials should have the lowest density under normal conditions? Which of the following materials should have the lowest density under normal conditions?
The densities of gases are much lower than that of solids and liquids
Which of the following would be most likely to be a liquid at room temperature? Which of the following is the best reason for your answer in the previous question?
The interaction between molecules is very weak so that they can easily move past one another
Which of the following would expand or contract less due to changes in temperature?
The lid of a pickle jar
Which of the following statements is incorrect?
The mass of 1 mole of carbon atoms is equal to the mass of 1 mole of boron atoms
A rectangular piece of metal is hammered into a thin sheet. Which of the following statements is true about the sheet of metal after being formed into the thin sheet?
The metal sheet has new dimensions, but the same volume as the original piece.
1 kg of lead is placed in pan A of the balance below by a student. The student then places 1 kg of Styrofoam in pan B. Which of the following best describes what the students should observe?
The pan would balance because both sides have the same amount of matter in them.
Which of the following is the best reason for why particles in a liquid and gas can diffuse and particles in a solid cannot?
The particles have space between one another
Which of the following can always be determined from only the empirical formula of a compound?
The percent composition of the elements by mass in the compound
Which of the following best describe why a material is considered neutral?
The positively charge in the material is balanced by the negative charge
A sample of water is brought to a boil. Which of the following is true while the water is boiling?
The temperature of the water remains constant
According to Avogadro's law, if two gases have the same pressure, temperature, and volume, which of the following must be true?
The two samples must have the same number of particles
Which of the following is always equal on each side of the arrow in a balanced chemical reaction?
Total number of atoms
Experiments with the cathode-ray tube demonstrated that
a cathode beam consists of particles that carried a negative charge
J.J. Thomson's experiments lead him to
conclude that atoms contained mobile particles that were negatively charged.
When a sample of liquid is cooled, its thermal energy
decreases
As atmospheric pressure decreases, the column of mercury in a barometer
decreases in height
If energy constantly needs to be supplied to a reaction in order for it to continue, the reaction would be considered a ______ reaction
endothermic
When a sample of gas is heated, the motion of the particles
increases
A sample of water is brought to a boil. After 30 minutes, inside a bubble in the boiling water are(is) _____
molecules of water
Two compounds contain both element A and element B. One compound contains twice as many grams of element B for each gram of element A than the other compound. This is an example of the law of
multiple proportions
Choose the best answer based on the Sticky Tape Lab observations to complete the following statement; "We could determine that the top piece of tape was
positive; because it was attracted to a negatively charged object
A reaction between aluminum and chlorine was studied to find the ratio of aluminum atoms to chlorine atoms. If the reaction was repeated with double the amount of aluminum to being with, the atom ratio between aluminum and chlorine would
remain the same
While a sample of liquid is freezing, its thermal energy
remains the same
According to Dalton's model of matter, atoms of elements
stick together in a defined ratio for a given compound
The pressure exerted by a gas in a container depends on
the number of collisions between gas particles and with the walls of the container
When gaseous water condenses to a liquid water, ____
the water releases energy to the surroundings
