1. Use the equation to answer the question.
CH4 + 2O2 → CO2 + 2H2O
If you change the 2 in front of 2O2 to a 3, what will be the change in the results on the right side of the equation?
a. there is an extra 02 molecule left over*
b. nothing changes in the equation
c. there are now 3H20 molecule
D. there are now 3CO2 molecules.
2. Which statement comparing ionic and covalent bonds is correct?
a. The difference between electronegativities is greater for atoms in covalent bonds than for atoms in ionic bonds.
b. Covalent bonds tend to be less polar than ionic bonds. *
c. Elements in Group IA are more likely to form covalent bonds than ionic bonds with other atoms.
d. More electrons are transferred to form covalent bonds than ionic bonds.
3. A chemical reaction produces a molecule in which all of the atoms have a stable configuration. Which molecule could be the product of the reaction?
a. PH3 *
B. SiO
C. MgBr
D. KCI2
Use the reaction to answer the question.
Zn + 2HCl → ZnCl2 + H2
Which type of reaction is this?
A. replacement *
B. electronegative
C. ionic
D. combustion
Two carbon atoms (Group 14) bond with two hydrogen atoms (Group 1) to form acetylene (C2H2). How would each carbon atom in acetylene bond?(1 point)
A. Each carbon atom would share one pair of electrons with the other carbon atom and three pairs with each hydrogen atom.
B. Each carbon atom would share one pair of electrons with hydrogen and one pair with the other carbon atom.
C. Each carbon atom would share one pair of electrons with the other carbon atom and two pairs with each hydrogen atom.
D. Each carbon atom would share one pair of electrons with hydrogen and three pairs with the other carbon atom. *
6. Use the equation to answer the question.
H2SO4 + HI → H2S + I2 + H2O
Which option shows a correctly balanced chemical equation?
A. H2SO4 + HI → H2S + I2 + H2O
B. 2H2SO4 + 2HI → 2H2S + I2 + 4H2O
C. H2SO4 + 8HI → H2S + 4I2 + 4H2O
D. H2SO4 + 8HI → H2S + 8I2 + 4H2O*
7. Use the equation to answer the question.
4NaCl + 2SO2 + _____H2O + _____O2 → _____Na2SO4 + 4HCl
Which numbers balance this equation?
A. 1,2,4
B. 2,1,4
C. 2,1,2 *
D. 1,2,2
8. Which statement describes the bonds in nitrate (NO3-)?
A. Nitrogen and oxygen have an electronegativity difference of 0.5, so the bond is polar covalent, with oxygen pulling the electrons toward it. *
B. Nitrogen and oxygen have an electronegativity difference of 0.5, so the bond is nonpolar covalent.
C. Nitrogen and oxygen have an electronegativity difference of 0.5, so the bond is polar covalent, with nitrogen pulling the electrons toward it.
D. Nitrogen and oxygen have an electronegativity difference of 0.5, so the bond is ionic.
9. When table salt forms, which action occurs between the reacting elements?
A. Sodium donates an electron to chlorine.*
B. Chlorine donates an electron to sodium.
C. Sodium shares an electron with chlorine.
D. Chlorine exchanges an electron with sodium.
10. Which element gains two electrons to fill its outermost energy level?
A. fluorine(F)
B. magnesium(Mg)
C. lithium(Li)
D. selenium(Se)*
11. Which characteristic do electronegativity differences indicate about reactions between atoms?(1 point)
A. bond number
B. valence electron number
C. bond type*
D. compound energy storage
12. Use the electronegativity and valence electron information to answer the question.
H electronegativity: 2.2
H valence electrons: 1
C electronegativity: 2.55
C valence electrons: 4
O electronegativity: 3.44
O valence electrons: 6
Chemical weathering over hundreds of thousands of years formed modern caves. One form of chemical weathering occurs when carbon dioxide reacts with water to produce carbonic acid, H2CO3. How many bonds formed in H2CO3?
A. eight
B. six *
C. three
D. five
13: Which element is most likely to react with Br?
A. Sr
B. O
C. K*
D. Ar
14. Which term refers to a substance that changes color when there is a certain concentration of hydrogen ions in a solution?
A. analyte
B. burette
C. titrant
D. indicator*
15. In three to five sentences, predict the bonding activity between phosphorous and chlorine. Why do you think they would bond that way?
16. When magnesium hydroxide reacts with nitric acid, it produces magnesium nitrate and water.
Mg(OH)2+2HNO3→Mg(NO3)2+2H2O
In one to two sentences, explain how this reaction demonstrates that matter is neither created nor destroyed in a chemical reaction.
17. Methane (CH4) is a gas that is found in small quantities in Earth’s atmosphere. Which type of bonds does methane have, and why does one carbon atom bond with four hydrogen atoms? In three to five sentences, explain your answer in terms of valence electrons and electronegativity.
18. A chemical reaction produces formaldehyde, with a chemical formula of CH2O. Carbon is in Group 4A, oxygen is in Group 6A, and hydrogen is in Group 1A on the periodic table. In one to two sentences, describe the bonds in a molecule of formaldehyde in terms of valence electrons
19. Use the reaction to complete the activity.
KOH + HBr → KBr + H2O
A student sets up a titration apparatus with 25 mL of potassium hydroxide in the flask. In three to five sentences, explain how the student can use a 0.1 M solution of hydrobromic acid to determine the concentration of potassium hydroxide in the reaction.
(I've completed the test. Just wanted to put this here to see if any of my answers were correct haha)
Better try again on 6. Your choice is not balanced; i.e., there are 8 I atoms on the left and 16 I atoms on the right.
The answers to 10 are NOT good choices but you've picked the best one there. Se does NOT gain two electrons to fill anything; however, it does SHARE two electrons.