Question

how many atoms of gallium? (1.4 points)
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5ga₂(cr₂o₇)₃
a. 5
b. 10
c. 15
d. 20
question 7 of 29
how many molecules of carbon dioxide are in following reaction? (6.8 points)
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6co₂ + 6h₂o → c₆h₁₂o₆ + 6o₂
a. 6
b. 12
c. 24
d. 2
question 8 of 29
how many atoms of potassium in this equation? (1.4 points)
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4k₂co₃
a. 2
b. 4
c. 6
d. 8

Explanation:

Step1: Analyze the first compound

In the formula \(5Ga_2(Cr_2O_7)_3\), the sub - script of \(Ga\) is \(2\) and there is a coefficient of \(5\) in front of the entire formula. The number of \(Ga\) atoms is calculated by multiplying the coefficient and the sub - script. So, the number of \(Ga\) atoms \(=5\times2 = 10\).

Step2: Analyze the chemical reaction for \(CO_2\)

In the reaction \(6CO_2+6H_2O
ightarrow C_6H_{12}O_6 + 6O_2\), the coefficient of \(CO_2\) is \(6\). The coefficient represents the number of molecules of \(CO_2\).

Step3: Analyze the second compound

In the formula \(4K_2CO_3\), the sub - script of \(K\) is \(2\) and the coefficient is \(4\). The number of \(K\) atoms is \(4\times2=8\).

Answer:

For the first question (gallium atoms): B. 10
For the second question (carbon dioxide molecules): A. 6
For the third question (potassium atoms): D. 8