Ask question

Ask question

All categories

2 years ago

14

How many formula units make up 15.0 g of magnesium chloride (MgCl2)?

1 answer:

tensa zangetsu [6.8K]2 years ago

8 0

The formula mass of MgCl - atomic mass of Mg + 2(atomic mass of Cl)
formula mass - 24.3 + (35.45x2) = 95.2
In 95.2 of MgCl₂ - there are 6.022 x 10²³ formula units of MgCl₂
Therefore in 15.0 g of MgCl2 - there are 6.022 x 10²³ /95.2 x 15.0 = 9.49 x 10²² formula units of MgCl₂
the number of formula units - 9.49 x 10²² formula units of MgCl₂

You might be interested in

What is the molarity (M) of the following solutions?

Dennis_Churaev [7]

Answer:

The molarity (M) of the following solutions are :

A. M = 0.88 M

B. M = 0.76 M

Explanation:

A. Molarity (M) of 19.2 g of Al(OH)3 dissolved in water to make 280 mL of solution.

Molar mass of Al(OH)3 = Mass of Al + 3(mass of O + mass of H)

= 27 + 3(16 + 1)

= 27 + 3(17) = 27 + 51

= 78 g/mole

$Al(OH)_3$ = 78 g/mole

Given mass= 19.2 g/mole

$Mole = \frac{Given\ mass}{Molar\ mass}$

$Mole = \frac{19.2}{78}$

Moles = 0.246

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

Volume = 280 mL = 0.280 L

$Molarity = \frac{0.246}{0.280)}$

Molarity = 0.879 M

Molarity = 0.88 M

B .The molarity (M) of a 2.6 L solution made with 235.9 g of KBr

Molar mass of KBr = 119 g/mole

Given mass = 235.9 g

$Mole = \frac{235.9}{119}$

Moles = 1.98

Volume = 2.6 L

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

$Molarity = \frac{1.98}{2.6)}$

Molarity = 0.762 M

Molarity = 0.76 M

4 0

2 years ago

De que depende la masa de un atomo?

patriot [66]

Answer:

depende en la gravedad

Explanation:

3 0

3 years ago

What is the volume (in dm3 of 1 mole of oxygen at 5 MPa and 200 K?

vodka [1.7K]

<u>Answer:</u> The volume of oxygen gas is $0.332dm^3$

<u>Explanation:</u>

To calculate the volume of the gas, we use the equation given by ideal gas equation:

$PV=nRT$

where,

P = pressure of the gas = 5 MPa = 5000 kPa (Conversion factor: 1 MPa = 1000 kPa)

V = Volume of gas = 3.34 L

n = number of moles of oxygen gas = 1 mole

R = Gas constant = $8.31dm^3\text{ kPa }mol^{-1}K^{-1}$

T = Temperature of the gas = 200 K

Putting values in above equation, we get:

$5000kPa\times V=1mol\times 8.31dm^3\text{ kPa }mol^{-1}K^{-1}\times 200K\\\\V=0.332dm^3$

Hence, the volume of oxygen gas is $0.332dm^3$

7 0

3 years ago

Organisms use different types of adaptations to aid in their survival.Some mushrooms are poisonous to organisms that eat them. W

Bogdan [553]

B A biochemical adaptation

5 0

2 years ago

Read 2 more answers

2. A book sits on a table. Which of the following is true?

vagabundo [1.1K]

Answer:

hi

Explanation:

4 0

3 years ago