Here are the answers to your questions:
Question 1
If you change the 2 in front of 2 O2 to a 3, what will be the change in the results on the right side of the equation?
- Response: There is an extra O2 molecule left over. (This also means that there would be an increase in other products like CO2 or H2O depending on the original equation.)
Question 2
Which statement comparing ionic and covalent bonds is correct?
- Response: Covalent bonds tend to be less polar than ionic bonds.
Question 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?
- Response: PH3 (because phosphorus is in Group 15 and can form a stable molecule with hydrogen)
Question 4
Which type of reaction is this? Zn + 2HCl → ZnCl2 + H2
- Response: replacement
Question 5
How would each carbon atom in acetylene bond?
- Response: Each carbon atom would share one pair of electrons with the other carbon atom and three pairs with each hydrogen atom.
Question 6
Which option shows a correctly balanced chemical equation? H2SO4 + HI → H2S + I2 + H2O
- Response: H2SO4 + 8HI → H2S + 4I2 + 4H2O
Question 7
Which numbers balance this equation? 4NaCl + 2SO2 + _____H2O + _____O2 → _____Na2SO4 + 4HCl
- Response: 2, 1, 4
Question 8
Which statement describes the bonds in nitrate (NO3-)?
- Response: Nitrogen and oxygen have an electronegativity difference of 0.5, so the bond is polar covalent, with oxygen pulling the electrons toward it.
Question 9
When table salt forms, which action occurs between the reacting elements?
- Response: Sodium donates an electron to chlorine.
Question 10
Which element gains two electrons to fill its outermost energy level?
- Response: Selenium (Se)
Question 11
Which characteristic do electronegativity differences indicate about reactions between atoms?
- Response: bond type
Question 12
How many bonds formed in H2CO3?
- Response: five (There are two H–O bonds and one C=O bond, and counting the resonance structure, there can be five effective bonds.)
Question 13
Which element is most likely to react with Br?
- Response: K (Potassium is an alkali metal that is likely to react with halogens like bromine.)
Question 14
Which term refers to a substance that changes color when there is a certain concentration of hydrogen ions in a solution?
- Response: indicator
If you have further questions or need clarification on any topic, feel free to ask!