All categories

3 years ago

How many pounds of coal would you have to burn to generate enough heat to boil a 15 l kettle?

1 answer:

7 0

Note that
The heating value of standard coal is about 30,080 kJ/kg
1 L of water has a mass of 1.0 kg

The mass of 15 L of water = 15 kg.
The latent heat of vaporization of water is about 2260 kJ/kg,
The energy required to boil 15 L of water is
(2260 kJ/kg)*(15 kg) = 33900 kJ

The mass of coal required to provide this energy is
(33900 kJ)/(30080 kJ/kg) = 1.127 kg

Because 1 kg = 2.205 lb, the mass of coal required is
(1.127 kg)*(2.205 lb/kg) = 2.485 lb

Answer: 2.49 lb (nearest hundredth)

You might be interested in

PLS HELP

alexandr1967 [171]

Answer:

Explanation:

A 12.48 g sample of an unknown metal, heated to 99.0 °C was then plunged into 50.0 mL of 25.0 °C water. The temperature of the water rose to 28.1 Go to calculating final temperature when mixing two samples of water ... Problem #1: A 610. g piece of copper tubing is heated to 95.3 °C and placed in an ... The two rings are heated to 65.4 °C and dropped into 12.4 mL of water at 22.3 °C. ... Problem #4: A 5.00 g sample of aluminum (specific heat capacity = 0.89 J g¯1

5 0

3 years ago

Read 2 more answers

Consider 100.0 g samples of two different compounds consisting only of carbon and oxygen. One compound contains 27.2 g of carbon

Pani-rosa [81]

Answer: The ratio of carbon in both the compounds is 1 : 2

Explanation:

Law of multiple proportions states that when two elements combine to form two or more compounds in more than one proportion. The mass of one element that combine with a given mass of the other element are present in the ratios of small whole number. For Example: $Cu_2O\text{ and }CuO$

For Sample 1:

Total mass of sample = 100 g

Mass of carbon = 27.2 g

Mass of oxygen = (100 - 27.7) = 72.8 g

To formulate the formula of the compound, we need to follow some steps:

Step 1: Converting the given masses into moles.

Moles of Carbon = $\frac{\text{Given mass of Carbon}}{\text{Molar mass of Carbon}}=\frac{27.2g}{12g/mole}=2.26moles$

Moles of Oxygen = $\frac{\text{Given mass of oxygen}}{\text{Molar mass of oxygen}}=\frac{72.8g}{16g/mole}=4.55moles$

Step 2: Calculating the mole ratio of the given elements.

For the mole ratio, we divide each value of the moles by the smallest number of moles calculated which is 2.26 moles.

For Carbon = $\frac{2.26}{2.26}=1$

For Oxygen = $\frac{4.55}{2.26}=2.01\approx 2$

Step 3: Taking the mole ratio as their subscripts.

The ratio of C : O = 1 : 2

Hence, the formula for sample 1 is $CO_2$

For Sample 2:

Total mass of sample = 100 g

Mass of carbon = 42.9 g

Mass of oxygen = (100 - 42.9) = 57.1 g

To formulate the formula of the compound, we need to follow some steps:

Step 1: Converting the given masses into moles.

Moles of Carbon = $\frac{\text{Given mass of Carbon}}{\text{Molar mass of Carbon}}=\frac{42.9g}{12g/mole}=3.57moles$

Moles of Oxygen = $\frac{\text{Given mass of oxygen}}{\text{Molar mass of oxygen}}=\frac{57.1g}{16g/mole}=3.57moles$

Step 2: Calculating the mole ratio of the given elements.

For the mole ratio, we divide each value of the moles by the smallest number of moles calculated which is 3.57 moles.

For Carbon = $\frac{3.57}{3.57}=1$

For Oxygen = $\frac{3.57}{3.57}=1$

Step 3: Taking the mole ratio as their subscripts.

The ratio of C : O = 1 : 1

Hence, the formula for sample 1 is $CO$

In the given samples, we need to fix the ratio of oxygen atoms.

So, in sample one, the atom ratio of oxygen and carbon is 2 : 1.

Thus, for 1 atom of oxygen, the atoms of carbon required will be = $\frac{1}{2}\times 1=\frac{1}{2}$

Now, taking the ratio of carbon atoms in both the samples, we get:

$C_1:C_2=\frac{1}{2}:1=1:2$

Hence, the ratio of carbon in both the compounds is 1 : 2

8 0

3 years ago

Which is a substance that could be found in air, water, or soil that is harmful to humans or animals? carbon dioxide fossil fuel

quester [9]

Hi!

The substance that could be found in air, water or soil that is harmful to humans or animals is called pollutant.

Pollutants are the only harmful substances that can be found in these three places. Carbon Dioxide (CO₂) is commonly found in the air, fossil fuels are found in soil and water and smog is found in the air. Only pollutant can be found in these three places as there are varied in its chemical structure. Common pollutants include Sulfur Dioxide (SO₂) which can be found in the air, and Lead, which can be found in water or soil.

Have a nice day!

4 0

3 years ago

What type(s) of intermolecular forces exist between two molecules of hexane? (BLB Ch. 11)

kati45 [8]

Answer:

induced dipole-dipole forces or London Dispersion forces / van der Waals forces.

Explanation:

Hexane is non-polar in nature. This is due to :

The bond in the molecule is C-H, which is non-polar in nature because the carbon and the hydrogen having very similar electronegativity values.

Hexane is also symmetric.

The intermolecular force acting in the molecule of the hexane are induced the dipole-dipole forces or London Dispersion forces / van der Waals forces.

7 0

3 years ago

What are all included in the immune response? A) T-cells B) lymphocytes C) B-cells D) stem cells E) oil

sergij07 [2.7K]

Answer: In the immune responds B,D are correct

Explanation:

I know this because i already learned it

8 0

2 years ago

Read 2 more answers