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3 years ago

Calculate the amount of heat released to convert 150.0 g of to water to ice at 0ºC.

Chemistry

2 answers:

gladu [14]3 years ago

8 0

Answer:

There correct answer is option 1 (-50100 J)

Explanation:

Step 1: Data given

Mass of water = 150.0 grams

ΔHfus = 334 J/g

Temperature = 0°C

ΔHfus = the amount of energy needed to change phase of 1 mol water to ice

Step 2: Calculate the amount of heat required

Q = m*ΔHfus

⇒Q = the amount of heat reuired = TO BE DETERMINED

⇒m =the mass of water = 150.0 grams

⇒ΔHfus = 334 J/g

Q = 150.0 grams * 334 J/g

Q = 50100 J of heat required

Step 3: Calculate heat released

Qrequired = -Q released

Qreleased = -50100 J

There correct answer is option 1 (-50100 J)

Svetlanka [38]3 years ago

7 0

Answer:

The answer is -50100 J

Explanation:

I just took the test as I'm in GCA as well (11th grade). My teacher walked us through each formula and gave us multiple practice questions in Jigsaw.

Honestly, all you need to be aware of is the fusion formula which is:

q = m*Hfusion

q = amount of energy

m = mass in grams

Hfusion = 334 J/g (it will not change)

Write down what we're given and what we're looking for:

q = ?

m = 150

Hfusion = 334 J/g

Set up the equation:

q = 150 * 334

Multiply 150 by 334 to get 50100.

You must keep in mind that we're finding how much heat is released which means the energy will be negative.

Add the negative sign to the number to get -50100 Joules

I don't know why that chart is there, it doesn't do anything for this equation. Disregard it for this problem.

Hope I helped! :D

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Which will NOT occur when a light tray ray interacts with a smooth pane of glass?

zhuklara [117]

Answer:

B) diffraction

Explanation:

A smooth pane of glass does not diffract light. A light passing through a smooth pane of glass may be absorbed, reflected or transmitted.

Diffraction only occurs with special types of glasses embedded with a diffraction grating and are called super prisms. Diffraction glasses use a a gradient lens which is able to separate light into all the colors of the rainbow.

Recall that diffraction is the separation of white light into its component wavelengths.

5 0

3 years ago

The attraction of like water molecules to each other is called _____.

Amiraneli [1.4K]

The attraction of like water molecules to each other is called cohension

7 0

3 years ago

How many molecules of carbon dioxide are dissolved in 0.550 L of water at 25 °C if the pressure of CO2 above the water is 0.250

Grace [21]

<u>Answer:</u> The number of molecules of carbon dioxide gas are $2.815\times 10^{21}$

<u>Explanation:</u>

To calculate the molar solubility, we use the equation given by Henry's law, which is:

$C_{CO_2}=K_H\times p_{CO_2}$

where,

$K_H$ = Henry's constant = $0.034mol/L.atm$

$C_{CO_2}$ = molar solubility of carbon dioxide gas

$p_{CO_2}$ = pressure of carbon dioxide gas = 0.250 atm

Putting values in above equation, we get:

$C_{CO_2}=0.034mol/L.atm\times 0.250atm\\\\C_{CO_2}=8.5\times 10^{-3}M$

To calculate the number of moles for given molarity, we use the equation:

$\text{Molarity of the solution}=\frac{\text{Moles of solute}}{\text{Volume of solution (in L)}}$

Molarity of carbon dioxide = $8.5\times 10^{-5}M$

Volume of solution = 0.550 L

Putting values in above equation, we get:

$8.5\times 10^{-3}M=\frac{\text{Moles of }CO_2}{0.550L}\\\\\text{Moles of }CO_2=(8.5\times 10^{-3}mol/L\times 0.550L)=4.675\times 10^{-3}mol$

According to mole concept:

1 mole of a compound contains $6.022\times 10^{23}$ number of molecules

So, $4.675\times 10^{-3}$ moles of carbon dioxide will contain = $(6.022\times 10^{23}\times 4.675\times 10^{-3})=2.815\times 10^{21}$ number of molecules

Hence, the number of molecules of carbon dioxide gas are $2.815\times 10^{21}$

3 0

3 years ago

Read 2 more answers

Helppppp with this pleasee

vazorg [7]

Answer:

A. 1, 2, 5

Explanation:

Count the number of Ns in the formula.

- Hope that helped! Please let me know if you need a further explanation.

3 0

3 years ago

WS Percent yield don’t understand how to do would appreciate the help

Grace [21]

Answer:

1. Theoretical yield of NaOH is 22.72 g

2. Percentage yield of NaOH = 22.14%

Explanation:

We'll begin by writing the balanced equation for the reaction. This is illustrated below:

NaHCO₃ —> NaOH + CO₂

From the balanced equation above,,

1 mole of NaHCO₃ decomposed to produce 1 mole (i.e 40 g) of NaOH and 1 mole (i.e 44.01 g) of CO₂.

Next, we shall determine the number of mole of NaHCO₃ that will decompose to produce 25 g of CO₂. This can be obtained as follow:

From the balanced equation above,,

1 mole of NaHCO₃ decomposed to produce 44.01 g of CO₂.

Therefore, Xmol of NaHCO₃ will decompose to 25 g of CO₂ i.e

Xmol of NaHCO₃ = 25 / 44.01

Xmol of NaHCO₃ = 0.568 mole

1. Determination of the theoretical yield of NaOH.

From the balanced equation above,,

1 mole of NaHCO₃ decomposed to produce 40 g of NaOH.

Therefore, 0.568 mole of NaHCO₃ will decompose to produce = 0.568 × 40 = 22.72 g of NaOH.

Thus, the theoretical yield of NaOH is 22.72 g

2. Determination of the percentage yield of NaOH.

Theoretical yield of NaOH = 22.72 g

Actual yield of NaOH = 5.03 g

Percentage yield of NaOH =?

Percentage yield = Actual yield /Theoretical yield × 100

Percentage yield = 5.03 / 22.72 × 100

Percentage yield of NaOH = 22.14%

4 0

3 years ago