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3 years ago

Boyle's law states that the

1 answer:

3 0

The correct answer is A. The volume of a gas varies inversely with pressure. Boyle's law is one of the gas laws we have. According to this law, at a fixed amount of an ideal gas which is at constant temperature, the pressure and volume are inversely proportional with each other.

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The average propane cylinder for a residential grill holds approximately 18 kg of propane. How much energy (in kJ) is released b

brilliants [131]

Combustion is a chemical reaction between a fuel and an oxidant, oxygen, to give off combustion products and heat. Complete combustion results when all of the fuel is consumed to form carbon dioxide and water, as in the case of a hydrocarbon fuel. Incomplete combustion results when insufficient oxygen reacts with the fuel, forming soot and carbon monoxide.

The complete combustion of propane proceeds through the following reaction:
$C_{3} H_{8}$ + $5O_{2}$ --> $3CO_{2}$ + $4H_{2}O$

Combustion is an exothermic reaction, which means that it gives off heat as the reaction proceeds. For the complete combustion of propane, the heat of combustion is (-)2220 kJ/mole, where the minus sign indicates that the reaction is exothermic.

The molar mass of propane is 44.1 grams/mole. Using this value, the number of moles propane to be burned can be determined from the mass of propane given. Afterwards, this number of moles is multiplied by the heat of combustion to give the total heat produced from the reaction of the given mass of propane.

14.50 kg propane x 1000 g x 1 mole propane x 2220 kJ 
1 kg 44.1 g 1 mole

= 729,931.97 kJ

8 0

3 years ago

A buffer solution contains 0.479 M NaHCO3 and 0.342 M Na2CO3. Determine the pH change when 0.091 mol HNO3 is added to 1.00 L of

pshichka [43]

Answer:

ΔpH = 0.20

Explanation:

The buffer of HCO₃⁻ + CO₃²⁻ has a pka of 10.2

HCO₃⁻ ⇄ H⁺ + CO₃²⁻

There are 0.479moles of NaHCO₃ and 0.342moles of Na₂CO₃.

Using Henderson-Hasselbalch formula:

pH = pka + log [Base] / [Acid]

pH = 10.2 + log 0.342mol / 0.479mol

pH = 10.05

NaOH reacts with HCO₃⁻ producing CO₃²⁻, thus:

NaOH + HCO₃⁻ → CO₃²⁻ + H₂O + Na⁺

0.091 moles of NaOH produce the same moles of CO₃²⁻ and consume HCO₃⁻. Moles of these species are:

CO₃²⁻: 0.342mol + 0.091mol: 0.433mol

HCO₃⁻: 0.479mol - 0.091 mol: 0.388mol

Using Henderson-Hasselbalch formula:

pH = pka + log [Base] / [Acid]

pH = 10.2 + log 0.433mol / 0.388mol

pH = 10.25

That means change of pH, ΔpH is:

ΔpH = 10.25 - 10.05 = 0.20

I hope it helps!

3 0

3 years ago

The following reaction is found to be at equilibrium at 25 celcius: 2SO3--->O2 + 2SO2 + 198kJ/mol. If the value for Kc at 25

kondaur [170]

Answer:

D.) Products are weakly favored

Explanation:

For the reaction:

2SO₃ ⇄ O₂ + 2SO₂ + 198kJ/mol

The kc is defined as:

kc = [O₂] [SO₂]² / [SO₃]²

As the kc is 8,1:

8,1 [SO₃]² = [O₂] [SO₂]²

The products are favored 8,1 times. This is a weakly favored because the usual kc are in the order of 1x10⁴. Thus, right answer is:

D.) Products are weakly favored

I hope it helps!

4 0

3 years ago

___________ minerals are dark-colored because they contain _____________. a. Mafic; iron and/or magnesium b. Felsic; iron and/or

Likurg_2 [28]

Answer:

A. Mafic; iron and/or magnesium

Explanation:

Let's find the answer by naming some minerals and their chemistry.

Mafic minerals are dark-colored whereas felsic minerals are light-colored, thats way mafic rocks are dark-colored because they are mainly composed by mafic minerals and the other way around for felsic rocks.

But remember that mafic minerals as amphiboles, pyroxenes or biotites, involve in their chemical structure iron and/or magnesium. Although calcium and sodium can be incorporated in amphiboles and clinopyroxenes, they are not involved in orthopyroxenes and biotites. On the other hand, although potassium is involved in biotite and in some extent in amphiboles, this element is not involved in pyroxenes.

So in conclusion, mafic minerals are usually dark-colored because they involve iron and/or magnesium in their chemical structures.

4 0

3 years ago

in this punnett square what is the ratio of homozgous to heterozygous offspring? in the punnett square what percentage of the of

Elina [12.6K]

Idk if this is a ratio but I know the percentage will be 3/4 Tt and 1/4 tt so Tt is 75% tt is 25%

8 0

3 years ago