Calculate the molar mass of aluminum oxide (Al2O3). Express your answer to four significant figures.

La masa de una olla es de 300g y contiene 90% de aluminio. Hallar el número de moles de aluminio de la olla. P.A.(Al= 27)

Neko [114]

Explanation:

The mass of a pot is 300g and contains 90% aluminum. Find the number of moles of aluminum in the pot. P.A. (Al = 27)

The mass of aluminum present in the pot is:

$300 g * 90/100\\=270 g$

Hence, in the given pot 270g Al is present.

$Number of moles of Al=\frac{given mass ofAl}{its molar mass}$

The gram atomic mass of Al -27 g/mol

Given the mass of Al is 270 g

Substitute these values in the above formula:

$Number of moles of Al=\frac{given mass ofAl}{its molar mass}\\=\frac{270 g}{27 g} \\=10.0 mol$

Answer is 10.0 mol of Al is present.

6 0

2 years ago

Pls it’s urgent

Rainbow [258]

Answer:

0.02 moles.

Explanation:

volume of H₂ gas at R.T.P = 480 cm³

Where

R.T.P = room temperature and pressure

molar volume of gas at = 24000 cm³

no. of moles of hydrogen = ?

Solution:

formula Used

no. of moles = volume of gas / molar volume

put values in above equation

no. of moles = 480 cm³ / 24000 cm³/mol

no. of moles = 0.02 mol

So,

no. of moles of hydrogen in 480 cm³ is 0.02 moles.

4 0

2 years ago

Match the following aqueous solutions with the appropriate letter from the column on the right.1. 0.19 m AgNO3 2. 0.17 m CrSO4 3

vichka [17]

Answer:

0.13 m of $Mn(NO_3)_2$ → Highest boiling point

0.19 m of $AgNO_3$ → Second Highest boiling point

0.17 m of $CrSO_4$ → Third highest boiling point

0.31 m Sucrose (nonelectrolyte) → Lowest boiling point

Explanation:

Elevation in boiling is given by :

$\Delta T_b=i\times k_b\times m$

Where :

i = van't Hoff factor

$k_b$ = Molal Elevation constant of solvent

m = molaity of the solution

1) 0.19 m of $AgNO_3$

$AgNO_3\rightarrow Ag^++NO_3^{-}$

i = 2 (electrolyte)

Molality of the solution = 0.19

Elevation is boiling point of solution:

$\Delta T_b=2\times k_b\times 0.19 m$

$\Delta T_b=0.38 m\times k_b$

2) 0.17 m of $CrSO_4$

$CrSO_4\rightarrow Cr^{2+}+SO_4^{2-}$

i = 2 (electrolyte)

Molality of the solution = 0.17

Elevation is boiling point solution :

$\Delta T_b=2\times k_b\times 0.17 m$

$\Delta T_b=0.34 m\times k_b$

3) 0.13 m of $Mn(NO_3)_2$

$Mn(NO_3)_2\rightarrow Mn^{2+}+2NO_3^{-}$

i = 3 (electrolyte)

Molality of the solution = 0.13

Elevation is boiling point solution :

$\Delta T_b=3\times k_b\times 0.13 m$

$\Delta T_b=0.39 m\times k_b$

4) 0.31 m Sucrose (nonelectrolyte)

i = 1 ( non electrolyte)

Molality of the solution = 0.31 m

Elevation is boiling point solution :

$\Delta T_b=1\times k_b\times 0.31 m$

$\Delta T_b=0.31 m\times k_b$

Higher the value of elevation in temperature higher will be the boiling point of the solution .

The decreasing order of solution from highest boiling point to lowest boiling point is :

$0.39 m\times k_b>0.38 m\times k_b>0.34 m\times k_b>0.31 m\times k_b$

0.13 m of $Mn(NO_3)_2$ → Highest boiling point

0.19 m of $AgNO_3$ → Second Highest boiling point

0.17 m of $CrSO_4$ → Third highest boiling point

0.31 m Sucrose (nonelectrolyte) → Lowest boiling point

6 0

3 years ago

I need help with this question 20 points and brainiest if ur right

Nutka1998 [239]

Answer:

The volume is 8 cm³

3 0

2 years ago

Read 2 more answers

A vapor is which state of matter? a. solid b. liquid c. gas d. all of the above

Yanka [14]

A vapor is which state of matter?

C. Gas.

8 0

3 years ago