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3 years ago

The density of solid Cr is 7.15 g/cm3. How many atoms are present per cubic centimeter of Cr?

1 answer:

8 0

To calculate the number of atoms of Cr, we first find the number of moles per unit of cubic centimeter of Cr. Then, use avogadros number for the number of atoms. Calculations are as follows:

1 cm^3 (7.15 g/cm^3) (1 mol / 51.996 g Cr) = 0.14 mol Cr

0.14 mol Cr ( 6.022 x 10^23 atoms Cr / 1 mol Cr ) = 8.28 x 10^22 atoms Cr

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POINTSSS!!!!!!

Lelu [443]

1 mole CO₂----------- 6.02x10²³ molecules
4 moles CO₂ ---------- ??

4 x ( 6.02x10²³) / 1 =

= 2.41 x 10²⁴ / 1 => 2.41 x 10²⁴ molecules of CO₂

Answer C

4 0

3 years ago

Determine the volume of a substance that has a density of 1.84 g/ml and a mass of 12 grams

vazorg [7]

Hey there!:

density = mass / volume

1.84 g/mL = 12 g / V

V = 12 / 1.84

V = 6.521 mL

hope this helps!

5 0

3 years ago

What is the pressure inside a 2.0 L bottle filled with 0.25 mol of carbon dioxide gas at 25 °C?

motikmotik

Answer:

3.1atm

Explanation:

Given parameters:

Volume of gas = 2L

Number of moles = 0.25mol

Temperature = 25°C = 25 + 273 = 298K

Unknown:

Pressure of the gas = ?

Solution:

To solve this problem, we use the ideal gas equation.

This is given as;

PV = nRT

P is the pressure

V is the volume

n is the number of moles

R is the gas constant = 0.082atmdm³mol⁻¹K⁻¹

T is the temperature

P = $\frac{nRT}{V}$

Now insert the parameters and solve;

P = $\frac{0.25 x 0.082 x 298}{2}$ = 3.1atm

8 0

3 years ago

The sum of protons and neutrons in an atom is called the.

tresset_1 [31]

Atomic mass / mass number / atomic weight

(all of which mean the same thing)

6 0

2 years ago

Hydroxide is an example of _______ and it's formula is OH-.

Ksju [112]

Answer:

polyatomic ion

Explanation:

It is polyatomic ion have a great day marry christmass

6 0

3 years ago