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Tom [10]
2 years ago
12

How many years ago were seven score and four years ago? (a score means 20)

Chemistry
1 answer:
Zina [86]2 years ago
6 0

144 years, its simple math?

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A chemist prepares a solution of copper(II) fluoride by measuring out of copper(II) fluoride into a volumetric flask and filling
Simora [160]

The question is incomplete, here is the complete question.

A chemist prepares a solution of copper(II) fluoride by measuring out 0.0498 g of copper(II) fluoride into a 100.0mL volumetric flask and filling the flask to the mark with water.

Calculate the concentration in mol/L of the chemist's copper(II) fluoride solution. Round your answer to 3 significant digits.

<u>Answer:</u> The concentration of copper fluoride in the solution is 4.90\times 10^{-3}mol/L

<u>Explanation:</u>

To calculate the molarity of solute, we use the equation:

\text{Molarity of the solution}=\frac{\text{Mass of solute}\times 1000}{\text{Molar mass of solute}\times \text{Volume of solution (in mL)}}

We are given:

Given mass of copper (II) fluoride = 0.0498 g

Molar mass of copper (II) fluoride = 101.54 g/mol

Volume of solution = 100.0 mL

Putting values in above equation, we get:

\text{Molarity of copper (II) fluoride)=\frac{0.0498\times 1000}{101.54\times 100.0}\\\\\text{Molarity of copper (II) fluoride}=4.90\times 10^{-3}mol/L

Hence, the concentration of copper fluoride in the solution is 4.90\times 10^{-3}mol/L

4 0
3 years ago
Help! I don't have the things to do this and its due TODAY! Could someone help me?
vodomira [7]

Answer:

--- The hot air inside the bottle creates an expansion and when the hot water is applied a contraction occurs, thus causing the balloon to be sucked.

--- An internal pressure is produced, joining the heat begins to decrease. As a consequence, the air molecule causes the balloon to enter the bottle thanks to the effect of the external pressure.

Explanation:

I hope I have helped with something.

4 0
3 years ago
Read 2 more answers
Imagine a 15kg block moving with a speed of 20m/s. Calculate the kinetic energy of this block.
SSSSS [86.1K]

The kinetic energy formula is;

  • KE=\frac{m.v^2}{2}

The variable m represents the mass. Its unit is kilogram. We are informed that the mass of the object is 15kg. The variable v represents the linear velocity. Its unit is meter per second. We are informed that the linear velocity of the object is 20m/s. Let's find the kinetic energy of the object by substituting these values in the formula.

  • KE=\frac{15kg.(20m/s)^2}{2}
  • 2.KE=15kg.400m^2/s^2
  • 2.KE=(6000)kgm^2/s^2
  • KE=(3000)kgm^2/s^2=3000J
5 0
1 year ago
8.) If 396 g of Carbon Dioxide (CO2) are produced, what mass of Oxygen<br> (02) reacted? *
Brut [27]

Answer:

264g

Explanation:

C + O2 -> CO2

_g + _g -> 396g

396÷3=132

C (132g) + O2 (264g) -> CO2 (396g)

7 0
2 years ago
When a hot dog is cooked, is that a physical change or chemical change
kifflom [539]
Its a Chemical change
4 0
3 years ago
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