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Hatshy [7]
3 years ago
9

When heating a flammable or volatile solvent for a recrystallization, which of these statements are correct? More than one answe

r may be correct.
a. You should not use an open flame to heat the solvent.
b. You should heat the solvent in a stoppered flask to keep vapor away from any open flames.
c. You should ensure that no one else is using an open flame near your experiment.
Chemistry
2 answers:
Citrus2011 [14]3 years ago
6 0

Answer:

You should not use an open flame to heat the solvent and the solvent should be heat in a stoppered flask to vapour away from the open flame

Explanation:

ruslelena [56]3 years ago
4 0

Answer:

A

Explanation:

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How many moles of glucose can be produced
Arturiano [62]

Answer:

moles of glucose

<u>2.3166 moles of glucose</u>

<u></u>

Explanation:

The balance reaction for the formation of glucose is :

6CO_{2}+6H_{2}O\rightarrow C_{6}H_{12}O_{6}+6O_{2}

here , CO2 = carbon dioxide

H2O = water

C6H12O6 = glucose

O2 = Oxygen

According to this equation :

6 mole of CO2 = 6 mole of H2O = 1 mole of C6H12O6 = 6 mole of O2

We are asked to calculate the mole of Glucose from carbon dioxide.

So,

6 mole of CO2  produce = 1 mole of C6H12O6

1 mole of CO2 will produce =

\frac{1}{6} moles of glucose

13.9 moles of CO2 will produce :

\frac{1}{6}\times 13.9

=2.3166 moles of glucose

Note : first , Always calculate for one mole (By dividing)

. After this , multiply the answer with the moles given.

Always write the substance whose amount is asked(glucose) to the right hand side

5 0
4 years ago
What is the mass of oxygen in 3.34 g of potassium permanganate?
3241004551 [841]

Answer:

1.35 g

Explanation:

Data Given:

mass of Potassium Permagnate (KMnO₄) = 3.34 g

Mass of Oxygen: ?

Solution:

First find the percentage composition of Oxygen in Potassium Permagnate (KMnO₄)

So,

Molar Mass of KMnO₄ = 39 + 55 + 4(16)

Molar Mass of KMnO₄ = 158 g/mol

Calculate the mole percent composition of  Oxygen in Potassium Permagnate (KMnO₄).

Mass contributed by Oxygen (O) = 4 (16) = 64 g

Since the percentage of compound is 100

So,

                        Percent of Oxygen (O) = 64 / 158 x 100

                        Percent of Oxygen (O) = 40.5 %

It means that for ever gram of Potassium Permagnate (KMnO₄) there is 0.405 g of Oxygen (O) is present.

So,

for the 3.34 grams of Potassium Permagnate (KMnO₄) the mass of Oxygen will be

                  mass of Oxygen (O) = 0.405 x 3.34 g

                  mass of Oxygen (O) = 1.35 g

5 0
3 years ago
A sample of food containing 27 g of fat, 48 g of carbohydrates and 20 g of protein is burned in a bomb calorimeter. In a perfect
rosijanka [135]

Answer:

38.3958 °C  

Explanation:

As,

1 gram of carbohydrates on burning gives 4 kilocalories  of energy

1 gram of protein on burning gives 4 kilocalories  of energy

1 gram of fat on burning gives 9 kilocalories of energy

Thus,

27 g of fat on burning gives 9*27 = 243 kilocalories of energy

20 g of protein on burning gives 4*20 = 80 kilocalories  of energy

48 gram of carbohydrates on burning gives 4*48 = 192 kilocalories  of energy

Total energy = 515 kilocalories

Using,

Q=m_{water}\times C_{water}\times (T_f-T_i)

Given: Volume of water = 23 L = 23×10⁻³ m³

Density=\frac{Mass}{Volume}  

Density of water= 1000 kg/m³

So, mass of the water:  

Mass\ of\ water=Density \times {Volume\ of\ water}  

Mass\ of\ water=1000 kg/m^3 \times {0.023\ m^3}  

Mass of water  = 23 kg

Initial temperature = 16°C  

Specific heat of water = 0.9998 kcal/kg°C  

515=23\times 0.9998\times (T_f-16)

Solving for final temperature as:

<u>Final temperature = 38.3958 °C  </u>

8 0
3 years ago
How many pencils are in 20 OWLS
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Owls means a mammalian species
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3 years ago
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The cell membrane responds to chemical signals from other cells A) true B) false
nataly862011 [7]
The answer would be A)true
8 0
4 years ago
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