True or false

Calculate the molecular mass of carbon dioxide (CO2):

Arisa [49]

The molecular mass is 44.01 g/mol

6 0

3 years ago

The cost of painting the circular traffic sign shown below is $3.50 per square foot. How much, to the nearest dollar, will it co

KiRa [710]

The cost of painting the traffic sign of 7.065 square feet is approximately equal to 25 dollar.

Explanation:

The cost of painting the circular traffic sign is given as 3.50 dollar per square feet. The diameter of the traffic sign is 36 inch, then its radius will be $\frac{36}{2} = 18$ inches.

But as the cost is given in unit of feet, we have to convert the radius from inches to feet.

1 inches = 0.0833 feet

18 inches = 18 × 0.0833 feet

So, the radius of the traffic sign will be approximately equal to 1.5 feet.

The area of the traffic sign will be $\pi r^{2} = 3.14 \times 1.5 \times 1.5 = 7.065$ square feet.

So, if the cost of painting 1 square feet of traffic sign is 3.50 dollar, then

cost of painting 7.065 square feet of traffic sign = 3.50 × 7.065 = 24.7 dollar.

Thus, the cost of painting the traffic sign of 7.065 square feet is approximately equal to 25 dollar.

8 0

3 years ago

37.5ml of menthol is dissolved in water to make 456 ml of solution, what is the concentration expressed in volume/volume % of th

Ahat [919]

Answer:

V/V% = 8.2%

Explanation:

Given data:

Volume of methanol = 37.5 mL

Volume of solution = 456 mL

V/V% = ?

Solution:

V/V% = [volume of solute / volume of solution ]×100

V/V% = 37.5 mL / 456 mL × 100

V/V% = 0.08× 100

V/V% = 8.2%

3 0

3 years ago

Determine the volume of a 0.800 M K2Cr2O7 solution required to completely react with 4.24 g of Cu.

Pachacha [2.7K]

Answer: The volume of solution required is 0.0275 L.

Explanation:

To calculate the number of moles, we use the equation:

$\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}$

Given mass of copper = 4.24 g

Molar mass of copper = 63.55 g/mol

Putting values in above equation, we get:

$\text{Moles of copper}=\frac{4.24g}{63.55g/mol}=0.067mol$

The chemical equation for the reaction of potassium dichromate and copper follows:

$K_2Cr_2O_7+3Cu+7H_2SO_4\rightarrow 3CuSO_4+Cr_2(SO_4)_3+K_2SO_4+7H_2O$

By Stoichiometry of the reaction:

3 moles of copper reacts with 1 mole of potassium dichromate.

So, 0.067 moles of copper will react with = $\frac{1}{3}\times 0.067=0.022mol$ of potassium dichromate

To calculate the volume of potassium dichromate, we use the equation:

$\text{Molarity of the solution}=\frac{\text{Moles of solute}}{\text{Volume of solution (in L)}}$

We are given:

Moles of potassium dichromate = 0.022 mol

Molarity of solution = 0.800 M

Putting values in above equation, we get:

$0.08mol/L=\frac{0.022mol}{\text{Volume of solution}}\\\\\text{Volume of solution}=0.0275L$

Hence, the volume of solution required is 0.0275 L.

6 0

3 years ago

What is the mass of 15 moles of carbon atoms? Round your answer to the nearest hundredth

Georgia [21]

In order to convert the moles of a substance to grams, you will need to multiply the mole value of the substance by its molar mass. More commonly written for this application as: where, is the molar mass of the substance.

Hope this helped

:)

4 0

3 years ago