Scientists believe that there are three genes that contribute to skin color in humans.

How many moles of KNO3 are in 500 mL of 2.0 M KNO3? ___ mol KNO3

weeeeeb [17]

Answer: 1mole

Explanation:

Mole = concentration× Volume (dm3)

Mole = 2× 500/1000

4 0

2 years ago

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Hydrogen fluoride is used in the manufacture of Freons (which destroy ozone in the stratosphere) and in the production of alumin

Lerok [7]

Answer: The percentage yield of HF is 73.36 %

Explanation:

To calculate the number of moles, we use the equation:

$\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}$ ....(1)

For calcium fluoride:

Given mass of calcium fluoride = 6.25 kg = 6250 g (Conversion factor: 1 kg = 1000 g)

Molar mass of calcium fluoride = 78.07 g/mol

Putting values in above equation, we get:

$\text{Moles of calcium fluoride}=\frac{6250g}{78.07g/mol}=80.05mol$

For the given chemical reaction:

$CaF_2+H_2SO_4\rightarrow CaSO_4+2HF$

By Stoichiometry of the reaction:

1 mole of calcium fluoride produces 2 moles of hydrofluoric acid

So, 80.05 moles of calcium fluoride will produce = $\frac{2}{1}\times 80.05=160.1mol$ of hydrofluoric acid

Now, calculating the theoretical yield of hydrofluoric acid using equation 1, we get:

Moles of of hydrofluoric acid = 160.1 moles

Molar mass of hydrofluoric acid = 20.01 g/mol

Putting values in equation 1, we get:

$160.1mol=\frac{\text{Theoretical yield of hydrofluoric acid}}{20.01g/mol}=3203.6g=3.20kg$

To calculate the percentage yield of hydrofluoric acid, we use the equation:

$\%\text{ yield}=\frac{\text{Experimental yield}}{\text{Theoretical yield}}\times 100$

Experimental yield of hydrofluoric acid = 2.35 kg

Theoretical yield of hydrofluoric acid = 3.20 kg

Putting values in above equation, we get:

$\%\text{ yield of hydrofluoric acid}=\frac{2.35g}{3.20g}\times 100\\\\\% \text{yield of hydrofluoric acid}=73.36\%$

Hence, the percentage yield of HF is 73.36 %

4 0

2 years ago

Look back at your data and your regression equation. (Sample data is shown to the right, with X= pressure and Y=volume.) click a

laiz [17]

Select the block of cells to be included in the scatter plot by clicking and dragging, then from the Insert ribbon under Chart drop down the Scatter or Bubble menu and select Scatter. A chart will appear on the spreadsheet.

To set up a scatter plot in Excel, enter the pairs of data in two columns with each value of a pair on the same row. By default, Excel considers the column on the left to contain the horizontal (X) values and the column on the right to contain the vertical (Y) values.

If you click on the + sign at the upper right of the chart, a list of checkboxes will appear. Check Axes, Axis Titles, and Trendline. Uncheck everything else. You should edit the Axis Titles to include the name of the factor and any units associated with it. Double-click on the Axis numbers to bring up the Format Axis dialog, then click on the bar-graph icon to access Axis Options. Set the bounds and units appropriately and set the tick marks to something sensible.

5 0

2 years ago

A diamond’s density is 3.2 g/cm3. Determine the volume of a diamond that has a mass of 1 g.

svetlana [45]

Answer:

https://socratic.org/questions/diamond-has-a-density-of-3-52-g-ml-what-is-the-volume-in-cubic-centimeters-of-a-

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2 years ago

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I need help name the parts of making up the female part of the flower and state what each part does. ( answer in your own unique

nekit [7.7K]

<h2>Answer:-</h2>

The female part is the pistil. The pistil usually is located in the center of the flower and is made up of three parts: the stigma, style, and ovary. The stigma is the sticky knob at the top of the pistil. It is attached to the long, tube like structure called the style.

6 0

1 year ago