Equation: 2Mg + O2 = 2MgO

Hydrogen peroxide decomposes to form water and oxygen gas according to the following equation: 2H2O2(aq)  2H2O(l) + O2(g) If 31

olya-2409 [2.1K]

Answer:

141.89 dm^3

Explanation:

The equation of the reaction is;

2H2O2(aq) --------->2H2O(l) + O2(g)

Now , we are told that the mass of hydrogen peroxide decomposed was 315g. Number of moles of hydrogen peroxide in 315g of the substance is given by;

Number of moles= mass/molar mass

Molar mass of hydrogen peroxide= 34.0147 g/mol

Number of moles= 315g/34.0147 g/mol = 9.26 moles of hydrogen hydrogen peroxide.

From the reaction equation;

2 moles of hydrogen peroxide yields 1 mole of oxygen

9.26 moles of hydrogen peroxide yields 9.26 ×1/2 = 4.63 moles of oxygen

From the ideal gas equation;

Volume of the gas V= the unknown

Pressure of the gas P= 0.792 atm

Temperature of the gas= 23°C +273 = 296 K

Number of moles of oxygen = 4.63 moles of oxygen

R= 0.082atmdm^3K-1mol-1

Hence, from PV=nRT

V= nRT/P

V= 4.63 × 0.082 × 296/0.792 = 141.89 dm^3

8 0

4 years ago

Which of the following characterizes a covalent bond?

Cloud [144]

Answer A. The electronegativity of one atom is less than 1.7

6 0

3 years ago

What is the empirical formula of a compound that contains 49.4% K, 20.3% S, and 30.3% by mass? A) KSO3 B) K2SO3 C) KSO2 D) KSO E

yulyashka [42]

Answer: $K_2SO_3$ .

Explanation:

If percentage are given then we are taking total mass is 100 grams.

So, the mass of each element is equal to the percentage given.

Mass of K = 49.4 g

Mass of S = 20.3 g

Mass of O = 30.3 g

Step 1 : convert given masses into moles.

Moles of K= $\frac{\text{ given mass of K}}{\text{ molar mass of K}}= \frac{49.4g}{40g/mole}=1.23moles$

Moles of S= \frac{\text{ given mass of S}}{\text{ molar mass of S}}= \frac{20.3g}{32g/mole}=0.63moles[/tex]

Moles of O = \frac{\text{ given mass of O}}{\text{ molar mass of O}}= \frac{30.3g}{16g/mole}=1.89moles[/tex]

Step 2 : For the mole ratio, divide each value of moles by the smallest number of moles calculated.

For K = $\frac{1.23}{0.63}=2$

For S = $\frac{0.63}{0.63}=1$

For O = $\frac{1.89}{0.63}=3$

The ratio of K: S:O = 2: 1: 3

Hence the empirical formula is $K_2SO_3$ .

7 0

4 years ago

The stigma on the underside of the leaf allows________to move in and out of the leaf

Kobotan [32]

Answer: carbon dioxide

Explanation:

Took the test

5 0

4 years ago

A soccer ball is traveling through an area of space, where there is no friction, at a speed of 25 m/s. If no unbalanced forces a

ivann1987 [24]

Answer:

Explanation:

40m/s

7 0

4 years ago