Question

class set - do not write on test!!!
midterm: chemistry 2025 - 2026 chemical equations and reactions
version b

1. how many molecules of carbon dioxide are in the following reaction?

6co₂ + 6h₂o → c₆h₁₂o₆ + 6o₂
a) 6
b) 12
c) 12
d) 2

1. which of the following sets of coefficients will balance the reaction below?

___ nabr + _ caf₂ → _ naf + ___ cabr₂
a) 4, 2, 4
b) 1, 2, 1, 2
c) 2, 3, 1, 2
d) 2, 1, 2, 1
what does the arrow in a chemical reaction represent?
a) yields
b) reacts to produce
c) combines to form
d) all of the above
a student left an iron nail outside for several weeks, and it formed redd
explanation best describes this chemical change?
a) the iron nail absorbed water and expanded physically.
b) the iron reacted with oxygen and moisture to form a n
c) the nail was only coated with dirt from the environm
d) the mass of the nail decreased because atoms were
what type of reaction is this? fe + o₂ → fe₂o₃
a) synthesis
b) decomposition
c) single replacement
d) double replacement

Explanation:

Step1: Analyze the chemical equation

In the equation \(6CO_{2}+6H_{2}O
ightarrow C_{6}H_{12}O_{6}+6O_{2}\), the coefficient of \(CO_{2}\) is 6. In a chemical equation, the coefficient represents the number of molecules (or moles) of a particular substance.

Answer:

A. 6