Question

one mole is equivalent to...
5.022 x 10²³ atoms.
6.2 x 10²³ atoms.
0.62 x 10²³ atoms.
6 022 x 10²³ atoms.
4 multiple choice 1 point
incomplete combustion happens when there is an insufficient supply of air. this is dangerous because it produces carbon monoxide, or co, a poisonous gas. what is the balancing coefficient for carbon monoxide in the incomplete combustion of propane gas?
2c₃h₈ + 9o₂ → 4co₂ + ?co + 8h₂o + heat
4
1
2
3

Explanation:

First Question (Mole Concept)

Step1: Recall Avogadro's Number

Avogadro's number is the number of particles (atoms, molecules, ions, etc.) in one mole of a substance. The value of Avogadro's number is approximately \( 6.022 \times 10^{23} \) particles per mole.

Step2: Evaluate the Options

• The first option \( 5.022 \times 10^{23} \) is incorrect.
• The second option \( 6.2 \times 10^{23} \) is an approximation but not the exact value.
• The third option \( 0.62 \times 10^{23} \) is incorrect.
• The fourth option \( 6.022 \times 10^{23} \) matches the value of Avogadro's number, which is the number of atoms (or particles) in one mole.

Step1: Count Carbon Atoms on Reactant Side

In the reactant \( 2C_3H_8 \), the number of carbon atoms is \( 2\times3 = 6 \) (since each \( C_3H_8 \) has 3 C atoms).

Step2: Count Carbon Atoms on Product Side

On the product side, we have \( 4CO_2 \) (which has 4 C atoms) and \(?CO \) (which has? C atoms). The total number of C atoms on the product side should equal the number on the reactant side (6). So, \( 4 +? = 6 \).

Step3: Solve for?

Solving \( 4 +? = 6 \), we get \(? = 6 - 4 = 2 \)? Wait, no, wait. Wait, let's re - check. Wait, the reactant is \( 2C_3H_8 \), so number of C atoms: \( 2\times3 = 6 \). On the product side, \( 4CO_2 \) has 4 C atoms, and \(?CO \) has? C atoms. So \( 4 +? = 6 \), so? = 2? Wait, but let's check again. Wait, maybe I made a mistake. Wait, the equation is \( 2C_3H_8+9O_2
ightarrow4CO_2 +?CO+8H_2O + Heat \). Wait, let's count C atoms:

Reactant: \( 2\times3 = 6 \) C atoms.

Product: \( 4CO_2 \) has 4 C atoms, \(?CO \) has? C atoms. So total C on product: \( 4 +? \).

Set equal to reactant C: \( 4+? = 6 \), so? = 2? But wait, the options have 2 as an option? Wait, no, wait the options are 4,1,2,3. Wait, maybe I miscalculated. Wait, no, let's check again. Wait, \( 2C_3H_8 \): 2 moles of \( C_3H_8 \), each has 3 C, so 6 C. On products: \( 4CO_2 \) (4 C) and \( xCO \) (x C). So \( 4 + x=6 \), so \( x = 2 \). Wait, but let's check oxygen as well to confirm.

Reactant O: \( 9O_2 \) has \( 9\times2 = 18 \) O atoms.

Product O: \( 4CO_2 \) has \( 4\times2 = 8 \) O, \( xCO \) has \( x\times1 = x \) O, \( 8H_2O \) has \( 8\times1 = 8 \) O. So total O on product: \( 8 + x+8=16 + x \).

Set equal to reactant O: \( 16 + x=18 \), so \( x = 2 \). So the coefficient of CO is 2.

Answer:

D. \( 6.022 \times 10^{23} \) atoms.

Second Question (Balancing Chemical Equation)