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3 years ago

5

In an area in which electricity costs 8 cents/kilowatt-hour, a 5 kW clothes dryer runs for 90 minutes to dry a load of laundry.

How much did it cost to dry these clothes?

1 answer:

Orlov [11]3 years ago

4 0

90 minutes is 1.5 hours.

5 kW * 1.5 hours = 7.5 kWh

8c/kWh * 7.5 kWh = 60 cents

You might be interested in

How many moles of SnCl2 will be produced if 85.3 g of FeCl3 is reacted with an excess of Sn for the following reaction:2 FeCl3(s

Ronch [10]

Answer:

The answer to your question is 0.79 moles of SnCl₂

Explanation:

Data

moles of SnCl₂ = ?

mass of FeCl₃ = 85.3 g

excess Sn

Balanced chemical reaction

2 FeCl₃ + 3 Sn ⇒ 3 SnCl₂ + 2 Fe

Process

1.- Convert the mass of FeCl₃ to moles

Molar mass of FeCl₃ = 56 + (35.5 x 3)

= 56 + 106.5

= 162.5 g

Use proportions to find the moles of FeCl₃

162.5 g -------------------- 1 mol

85.3 g ------------------- x

x = (85.3 x 1) / 162.5

x = 0.525 moles

2.- Find the number of moles SnCl₂

2 moles of FeCl₃ ----------------- 3 moles of SnCl₂

0.525 moles ----------------- x

x = (0.525 x 3) / 2

x = 0.79 moles of SnCl₂

4 0

4 years ago

An endothermic dissolution process a. absorbs energy as heat and has positive enthalpy of solution. b. releases energy as heat a

Whitepunk [10]

Answer:

a. absorbs energy as heat and has positive enthalpy of solution.

Explanation:

A reaction can either be exothermic or endothermic. An endothermic reaction, as the dissolution described in the question, is that which absorbs heat energy from the surroundings in order to start the reaction.

Because an endothermic reaction makes heat lost from the surroundings, the enthalpy (∆H) of the solution will be positive (+). ∆H is got by finding the difference between the enthalpy of the reactants and products and since the enthalpy of a product in endothermic reaction is more, the enthalpy change (∆T) will be positive.

8 0

3 years ago

Name three chemical properties of wood

Zielflug [23.3K]

Answer:

Burn, able to rust, and sour.

Explanation:

4 0

3 years ago

Mila [183]

Answer:

2KClO3 —> 2KCl + 3O2

The coefficients are 2, 2, 3

Explanation:

From the question given above, we obtained the following equation:

KClO3 —> 2KCl + 3O2

The above equation can be balance as follow:

There are 2 atoms of K on the right side and 1 atom on the left side. It can be balance by putting 2 in front of KClO3 as shown below:

2KClO3 —> 2KCl + 3O2

Now, the equation is balanced.

Thus, the coefficients are 2, 2, 3

8 0

3 years ago

A gas mixture with a total pressure of 745 mmHg contains each of the following gases at the indicated partial pressures: CO2, 24

Setler79 [48]

<u>Answer:</u>

<u>For Part A:</u> The partial pressure of Helium is 218 mmHg.

<u>For Part B:</u> The mass of helium gas is 0.504 g.

<u>Explanation:</u>

<u>For Part A:</u>

We are given:

$p_{CO_2}=245mmHg\\p_Ar}=119mmHg\\p_{O_2}=163mmHg\\P=745mmHg$

To calculate the partial pressure of helium, we use the formula:

$P=p_{CO_2}+p_{Ar}+p_{O_2}+p_{He}$

Putting values in above equation, we get:

$745=245+119+163+p_{He}\\p_{He}=218mmHg$

Hence, the partial pressure of Helium is 218 mmHg.

<u>For Part B:</u>

To calculate the mass of helium gas, we use the equation given by ideal gas:

PV = nRT

or,

$PV=\frac{m}{M}RT$

where,

P = Pressure of helium gas = 218 mmHg

V = Volume of the helium gas = 10.2 L

m = Mass of helium gas = ? g

M = Molar mass of helium gas = 4 g/mol

R = Gas constant = $62.3637\text{ L.mmHg }mol^{-1}K^{-1}$

T = Temperature of helium gas = 283 K

Putting values in above equation, we get:

$218mmHg\times 10.2L=\frac{m}{4g/mol}\times 62.3637\text{ L.mmHg }mol^{-1}K^{-1}\times 283K\\\\m=0.504g$

Hence, the mass of helium gas is 0.504 g.

6 0

3 years ago