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3 years ago

8

Why do you cool down tea extract in ice to below 40°c before adding dichloromethane?

1 answer:

jeyben [28]3 years ago

5 0

For drinking because it’s much cold

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Describe a dinner you would like to eat that includes all the main nutrients, but is low in the nutrients that you should limit.

IceJOKER [234]

The only food that provides all the nutrients that humans need is human milk," Hattner said. "Mother's milk is a complete food. We may add some solid foods to an infant's diet in the first year of life to provide more iron and other nutrients, but there is a little bit of everything in human milk.

6 0

2 years ago

A 3.50 amp power supply is used to deposit chromium from a solution of CrCl3. How long will it take to deposit 100.0 grams of ch

Norma-Jean [14]

Explanation:

The given data is as follows.

Current (I) = 3.50 amp, Mass deposited = 100.0 g

Molar mass of Cr = 52 g

It is known that 1 faraday of electricity will deposit 1 mole of chromium. As 1 faraday means 96500 C and 1 mole of Cr means 52 g.

Therefore, 100 g of Cr will be deposited by "z" grams of electricity.

$z \times 52 g = 96500 \times 100 g$

z = $\frac{96500 \times 100 g}{52 g}$

= 185576.9 C

As we know that, Q = I × t

Hence, putting the given values into the above equation as follows.

Q = I × t

185576.9 C = $3.50 amp \times t$

t = 53021.9 sec

Thus, we can conclude that 100 g of Cr will be deposited in 53021.9 sec.

3 0

3 years ago

How many atoms are in c8h8o3?<br> Show your work

Gelneren [198K]

Answer:

im positive that it's 19

8 0

3 years ago

A 5.000 g mixture contains strontium nitrate and potassium bromide. Excess lead(II) nitrate solution is added to precipitate out

scZoUnD [109]

<u>Answer:</u> The mass percent of potassium bromide in the mixture is 9.996%

<u>Explanation:</u>

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

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

<u>For lead (II) bromide:</u>

Given mass of lead (II) bromide = 0.7822 g

Molar mass of lead (II) bromide = 367 g/mol

Putting values in equation 1, we get:

$\text{Moles of lead (II) bromide}=\frac{0.7822g}{367g/mol}=0.0021mol$

The chemical equation for the reaction of lead (II) nitrate and potassium bromide follows:

$2KBr+Pb(NO_3)_2\rightarrow PbBr_2+2KNO_3$

By Stoichiometry of the reaction:

1 mole of lead (II) bromide is produced from 2 moles of potassium bromide

So, 0.0021 moles of lead (II) bromide will be produced from = $\frac{2}{1}\times 0.0021=0.0042mol$ of potassium bromide

Now, calculating the mass of potassium bromide by using equation 1, we get:

Molar mass of KBr = 119 g/mol

Moles of KBr = 0.0042 moles

Putting values in equation 1, we get:

$0.0042mol=\frac{\text{Mass of KBr}}{119g/mol}\\\\\text{Mass of KBr}=0.4998g$

To calculate the percentage composition of KBr in the mixture, we use the equation:

$\%\text{ composition of KBr}=\frac{\text{Mass of KBr}}{\text{Mass of mixture}}\times 100$

Mass of mixture = 5.000 g

Mass of KBr = 0.4998 g

Putting values in above equation, we get:

$\%\text{ composition of KBr}=\frac{0.4998g}{5.000g}\times 100=9.996\%$

Hence, the percent by mass of KBr in the mixture is 9.996 %

5 0

3 years ago

What is the formula for the ionic compound of strontium and chlorine?

Leno4ka [110]

The formula is SrCl2. hope this helps

8 0

3 years ago