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3 years ago

If you were asked to convert 4.2 × 1022 atoms of aluminum to moles, which of the following should you use for the conversion?

2 answers:

8 0

4.2×1022/NA is a: 
 $N_{A} is~ the~ Avogadro ~number$ $6.022 x 10^23~ a/m$ (a/m)= atoms and moles

gregori [183]3 years ago

4 0

You should use Avogadro’s number for the conversion, because Avogadro’s Law states that there are 6.02 x 10^23 atoms per 1 mol of that substance.

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The lead pipe has a mass of 200 g, how much will be left after 6 months?

kumpel [21]

Answer:

33g

Explanation:

200 divided by 6=33.33

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3 years ago

In what state of matter are the particles vibrating at high speeds?

OLEGan [10]

The answer would be C

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3 years ago

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.

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

Explanation:

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

2 years ago

Which of these would most likely be one of the final steps when performing a strong acid-base titration? Prepare the burette. Re

DanielleElmas [232]

Answer is: Prepare to measure pH change.

For example for strong acid-base titration, sodium hydoxide and hydrochloric can be used.

Balanced chemical reaction: HCl + NaOH → NaCl + H₂O.

In this reaction pH of equivalence point will be always 7.

Equivalence point is the point which there is stoichiometrically equivalent amounts of acid and base.

Chemist can draw pH curve (graph showing the change in pH of a solution, which is being titrated) for titration and determine equivalence point.

Near equivalence point indicator should change color, so we must pick indicator who change color near pH of equivalence point.

8 0

2 years ago

Read 2 more answers

How can you tell if a chemical equation is balanced

k0ka [10]

Answer:

A chemical equation is balanced when the number of each kind of atom is the same on both sides of the reaction.

Explanation:

The law of conservation of matter (except in nuclear reactions) indicates that atoms can neither be created or destroyed.

The number of atoms that are in the reactants must be the same as the number of the atoms that are in the product.

The number and types of molecules can (and will) change. The atoms that make up the molecules are rearranged but the number and kinds of atoms stay the same.

3 0

2 years ago