Jamie works at a company that makes

Three samples of a solid substance composed of elements A and Z were prepared. The first contained 4.31 g A and 7.70 g Z. The se

murzikaleks [220]

Answer:

The percentage composition of the elements of the compound in the three samples is the same.

Explanation:

<em>The law of definite proportions states that all pure samples of a particular chemical compound contain the same elements in the same proportion by mass.</em>

Sample A:

Mass of A = 4.31 g; mass of Z = 7.70 g

Total mass of sample = 12.01

Percentage mass of A in the sample = (4.31 * 100)/12.01 = 35.9 %

Percentage mass of Z in the sample = (7.70 * 100)/12.01 = 64.1 %

Sample B:

Percentage mass of A in the sample = 35.9 %

Percentage mass of Z in the sample = 64.1 %

Sample C:

Mass of A = 0.718 g; Total mass of sample = 2.00 g

mass of Z = mass of sample - mass of A = 2.00 g - 0.718 g = 1.282 g

Percentage mass of A in the sample = (0.718 * 100)/2.00 = 35.9 %

Percentage mass of Z in the sample = (1.282 * 100)/2.00 = 64.1 %

From the calculations, it can be seen that the percentage composition of the elements in the compound is the same for the three samples.

8 0

4 years ago

What is the net cell reaction for the cobalt-silver voltaic cell? express your answer as a chemical equation?

slava [35]

Answer: The net ionic equation for the cobalt-silver voltaic cell is $Co(s)+3Ag^+(aq.)\rightarrow Co^{3+}(aq.)+3Ag(s)$

Explanation: In cobalt-silver voltaic cell, one half of the cell consists of cobalt electrode immersed in $Co(NO_3)_3$ solution ( which means that $Co^{3+}$ are present in the solution) and other half of the cell consists of the Ag electrode immersed in $AgNO_3$ solution ( which means that $Ag^+$ is present in the solution)

The two electrodes are joined by the copper wire. The cobalt electrode acts as an anode and the silver electrode acts a cathode.

At anode, oxidation reaction takes place and at cathode, reduction reaction takes place.

At Anode : $Co(s)\rightarrow Co^{3+}(aq.)+3e^-$

At Cathode: $[Ag^+(aq.)+e^-\rightarrow Ag(s)]\times 3$

Net ionic equation: $Co(s)+3Ag^+(aq.)\rightarrow Co^{3+}(aq.)+3Ag(s)$

6 0

3 years ago

Hydrocarbons, compounds containing only carbon and hydrogen, are important in fuels. The heat of combustion of cyclopentane, C5H

pishuonlain [190]

Answer:

4664.54 kcal of energy is produced on the complete combustion of 416 grams of cyclopentane

Explanation:

Combustion is the process by which hydrocarbons react with oxygen to heat to produce heat energy.

The heat energy produced when one mole of an hydrocarbon is completely burnt or combusted in air is called the heat of combustion

The balanced equation for the complete combustion of cyclopentane (C5H10) is given below:

2C₅H₁₀ + 15O₂ → 10CO₂ + 10H₂O

ΔH combustion = 786.6 kcal/mol

What the above equation means is that each time one mole of cyclopentane is completely burnt, 786.6kcal of energy is released.

Hence we need to calculate the number of moles of cyclopentane in 416grams; therefore

No of moles cyclopentane = mass of cyclopentane / molar mass of cycopentane

= 416 g / 70.1 g/mol

= 5.9343moles

≅ 5.93 moles of cyclopentane in 416grams

From the question, since the cyclopentane is completely combusted, it implies that the energy released would be

1 mole of cyclopentane = 786.6 kcal of energy

5.93 moles of cyclopentane would produce

= 5.93 moles x 786.6kcal/mol

= 4664.54 kcal of energy

6 0

3 years ago

What happens to carbon in plants when the plants die.

Korvikt [17]

Answer:

Released into the atmosphere

Explanation:

The carbon that the plant had been storing when it was alive, would be released upon death into the soil

4 0

2 years ago

If you have 0.56 moles of an ideal gas at 87c and a pressure of 569 torr, what volume will the gas take up

Taya2010 [7]

The answer is volume equals 22 liters

6 0

3 years ago