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3 years ago

Why does nitrogen have the lowest volume in the atmosphere on average?

1 answer:

7 0

Nitrogen has the lowest volume in the atmosphere on average because the two gases make up approximately 99% of the dry atmosphere. <span />

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when carbon dioxide is bubbled through lime water the solution first turn milky and to colour less . Explain why these changes o

Annette [7]

Answer:

When excess of carbon dioxide is passed in lime water, calcium carbonate is converted to calcium bicarbonate which is soluble, hence the milkiness due to calcium carbonate disappears.

Explanation:

Ca(OH)2+CO2 → CaCO3 (Milkiness) ↓+H2O

CaCO3+H2O+CO2 → Ca(HCO3)2 (soluble)

5 0

3 years ago

Solution with a ph of 3 has how many times more h+ ions than one with a ph of 4? 5?

Lerok [7]

Solution with a pH of 3 has 10⁻³ moles of H⁺, solution with a pH of 4 has 10⁻⁴ moles of H⁺ and solution with a pH of 5 has 10⁻⁵ moles of H⁺ (in dm³) so the solution with a pH of 3 has 10 times more H⁺ ions than the solution with a pH of 4 and 100 times more H⁺ ions than the solution with a pH of 5.

8 0

3 years ago

What are two things that you observed when you heated the mixture of tin and nitric acid over the Bunsen burner in the virtual l

Rus_ich [418]

1. The reaction for this would be:

Sn + 4 HNO₃ → SnO₂ + 4 NO₂ + 2 H₂O

The first observation would be bubbling of the solution and brown acrid smoke is produced due to the presence of NO₂ gas. Another observation would be the presence of a white solid which is SnO₂.

2. Heating was required to get rid of the H₂O. When all moisture is gone, you weigh the sample. Afterwhich, you further heat it to get ride of the oxygen. By doing this, you would know the individual mass of each element. Then, you can solve for the empirical formula of the oxide of tin.

3 0

4 years ago

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

3 years ago

Determine total H for bonds broken and formed, the overall change in H, and the final answer with units. Is it ENDOthermic or EX

Mrac [35]

E(Bonds broken) = 1371 kJ/mol reaction
E(Bonds formed) = 1852 kJ/mol reaction

ΔH = -481 kJ/mol.
The reaction is exothermic.

<h3>Explanation</h3>

2 H-H + O=O → 2 H-O-H

There are two moles of H-H bonds and one mole of O=O bonds in one mole of reactants. All of them will break in the reaction. That will absorb

E(Bonds broken) = 2 × 436 + 499 = 1371 kJ/mol reaction.
ΔH(Breaking bonds) = +1371 kJ/mol

Each mole of the reaction will form two moles of water molecules. Each mole of H₂O molecules have two moles O-H bonds. Two moles of the molecule will have four moles of O-H bonds. Forming all those bond will release

E(Bonds formed) = 2 × 2 × 463 = 1852 kJ/mol reaction.
ΔH(Forming bonds) = - 1852 kJ/mol

Heat of the reaction:

$\Delta H_{\text{rxn}} = \Delta H(\text{Breaking bonds}) + \Delta H(\text{Forming bonds})\\\phantom{ \Delta H_{\text{rxn}}} = +1371 + (-1852) \\\phantom{ \Delta H_{\text{rxn}}} = -481 \; \text{kJ} / \text{mol}$

$\Delta H_{\text{rxn}}$ is negative. As a result, the reaction is exothermic.

3 0

3 years ago