Question : 1.              Identify which image in the figure represents the reactants : 1335424

1.              Identify which image in the figure represents the reactants and which image therefore represents the products in the reaction between xenon gas and fluorine gas to form xenon tetrafluoride gas.

A)upper left image = reactants, lower right image = products

B)upper left image = reactants, lower left image = products

C)upper left image = reactants, upper right image = products

D)upper right image = reactants, upper left image = products

E)lower left image = reactants, upper left image = products

2.              Identify which image in the figure represents the reactants and which image therefore represents the products in the reaction between ozone gas (O3) and carbon monoxide gas to form oxygen gas and carbon dioxide gas.

A)upper left image = reactants, lower right image = products

B)upper left image = reactants, lower left image = products

C)upper left image = reactants, upper right image = products

D)upper right image = reactants, upper left image = products

E)lower left image = reactants, lower right image = products

3.              The figure shows the chemical reaction between nitrogen gas and hydrogen gas to produce ammonia (NH3) gas.  Which of the following changes would make the diagram correctly represent conservation of mass?

A)Remove one H2 molecules from the image on the left.

B)Add one H2 molecule from the image on the left.

C)Add three H2 molecules t the image on the right.

D)Remove one NH3 molecule from the image on the left.

E)Add three NH3 molecules to the image on the right.

4.              The figure shows a reaction between methane gas (natural gas, CH4) and oxygen to produce carbon dioxide and water.  Is the diagram accurate, and if not, what is wrong with it, and how could it be fixed?

A)The diagram is accurate as shown.

B)There are too many oxygen atoms on the right-hand side of the reaction arrow.  Remove one oxygen atom from the carbon dioxide.

C)There are too many hydrogen atoms on the right-hand side of the reaction arrow.  Remove one hydrogen atom from each water molecule.

D)There are not enough carbon atoms on the left-hand side of the reaction arrow.  Add another methane molecule on the left, and then another carbon dioxide molecule on the right of the arrow.

E)There are not enough oxygen molecules on the left-hand side of the reaction arrow.  Add another oxygen molecule on the left of the arrow, and another water molecule on the right.

5.              The figure shows a reaction between hydrogen and oxygen gases to produce water.  Is the diagram accurate, and if not, what is wrong with it, and how could it be fixed?

A)The diagram is accurate as shown.

B)There are too many oxygen atoms in the image on the left.  Remove one oxygen molecule.

C)There are not enough oxygen atoms on the right.  Add one more water molecule to the right image.

D)There are not enough hydrogen atoms on the right.  Add one more water molecule to the left image, and one more hydrogen molecule to the right image.

E)There are too many water molecules on the right.  Remove one water molecule from the image on the right.

6.              The figure shows a reaction between xenon gas and fluorine gas.  Is the diagram correct, and if not, how could it be modified to show that the law of conservation of mass is obeyed?

A)The diagram is accurate as shown.

B)Add three more XeF4 molecules and one more Xe atom to the right image.

C)Add four more XeF4 molecules to the right image.

D)Add two more XeF4 molecules and two more Xe atoms to the right image.

E)Add one more XeF4 molecule and three more Xe atoms to the right image.

7.              Sulfur dioxide gas reacts with oxygen gas to form sulfur trioxide gas.  What would the products of the reaction be, if the reactants are those shown in the figure?

A)4 molecules of sulfur trioxide

B)3 molecules of sulfur trioxide, and 1 molecule of oxygen

C)4 molecules of sulfur trioxide, and 1 molecule of oxygen

D)2 molecules of sulfur trioxide, and 2 molecules of sulfur dioxide

E)3 molecules of sulfur trioxide, and 1 molecule of sulfur dioxide

8.              Gaseous nitrogen monoxide reacts with oxygen gas to form brown nitrogen dioxide gas.  What would the products of the reaction be, if the reactants are those shown in the figure?

A)6 molecules of nitrogen dioxide

B)5 molecules of nitrogen dioxide, and 1 molecule of oxygen

C)6 molecules of nitrogen dioxide, and 1 molecule of oxygen

D)4 molecules of nitrogen dioxide, and 2 molecules of nitrogen monoxide

E)3 molecules of nitrogen dioxide, and 3 molecules of nitrogen monoxide

9.              Which of the following changes represents a physical change, rather than evidence of a chemical reaction?

A)When a solution of KI is mixed with a solution of Pb(NO3)2, a yellow solid is formed.

B)When a piece of copper wire is placed in a solution of AgNO3, a silvery solid begins to form on the surface of the wire, and the solution turns blue.

C)When a piece of zinc metal is placed in a solution of HCl, bubbles begin to form, and the zinc begins to dissolve.

D)When dry ice (solid CO2) is allowed to stand at room temperature, a white cloud and gaseous CO2 are formed.

E)When solid ammonium carbonate, (NH4)2CO3, is heated, the solid disappears, and gaseous ammonia (NH3), carbon dioxide (CO2), and water (H2O) are formed.

10.              Which of the following changes represents a physical change, rather than evidence of a chemical reaction?

A)When solutions of AgNO3 and NaCl are mixed, a white solid forms.

B)When concentrated HNO3 is placed in contact with copper metal, a brown gas is formed, the copper dissolves, and a green solution is formed.

C)When water and a yellow solution of antifreeze are mixed, the resulting solution is a lighter shade of yellow than the original antifreeze solution.

D)When a piece of zinc metal is placed in a blue solution of copper sulfate, the solution turns from blue to colorless, the zinc dissolves, and copper metal is formed.

E)When an egg is fried, the clear part becomes white, and the egg becomes a solid.

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