Simple Reactions Unit Test *Answers*
i just took the test & it was pretty difficult to find some of the answers so i'm just gonna post them all on here! i'll also try to post the short answers as well once they get graded.
1) 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 O2 molecule left over.
2) Which statement comparing ionic and covalent bonds is correct?
C. Covalent bonds tend to be less polar 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?
B. PH3
4) Zn + 2HCl → ZnCl2 + H2
Which type of reaction is this?
B. replacement
5) Two carbon atoms (Group 14) bond with two hydrogen atoms (Group 1) to form acetylene (C2H2). How would each carbon atom in acetylene bond?
C. Each carbon atom would share one pair of electrons with hydrogen and three pairs with the other carbon atom.
6) H2SO4 + HI → H2S + I2 + H2O
Which option shows a correctly balanced chemical equation?
B. H2SO4 + 8HI → H2S + 4I2 + 4H2O
7) 4NaCl + 2SO2 + _____H2O + _____O2 → _____Na2SO4 + 4HCl
Which numbers balance this equation?
C. 2,1,2
8) Which statement describes the bonds in nitrate (NO3-)?
D. Nitrogen and oxygen have an electronegativity difference of 0.5, so the bond is polar covalent, with oxygen pulling the electrons toward it.
9) When table salt forms, which action occurs between the reacting elements?
A. Sodium donates an electron to chlorine.
10) Which element gains two electrons to fill its outermost energy level?
A. selenium (Se)
11) Which characteristic do electronegativity differences indicate about reactions between atoms?
C. bond type
12) 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. six
13) Which element is most likely to react with Br?
C. K
14) Which term refers to a substance that changes color when there is a certain concentration of hydrogen ions in a solution?
B. indicator
15) like i said i'll come back to post the short answers once the teacher grades them