All categories

3 years ago

What is the mass number of an atom?

Chemistry

2 answers:

Helen [10]3 years ago

4 0

Answer:

it’s total number of protons and neutrons

Gennadij [26K]3 years ago

3 0

The mass number of an atom is its total number of protons and neutrons. Atoms of different elements usually have different mass numbers , but they can be the same. For example, the mass number of argon atoms and calcium atoms can both be 40.

You might be interested in

One way in which the useful metal copper is produced is by dissolving the mineral azurite, which contains copper(II) carbonate,

alexgriva [62]

The question is incomplete, here is the complete question:

One way in which the useful metal copper is produced is by dissolving the mineral azurite, which contains copper(II) carbonate, in concentrated sulfuric acid. The sulfuric acid reacts with the copper(II) carbonate to produce a blue solution of copper(II) sulfate. Scrap iron is then added to this solution, and pure copper metal precipitates out because of the following chemical reaction:

Fe(s) + CuSO4 (aq) → Cu(s) + FeSO4 (aq)

Suppose an industrial quality-control chemist analyzes a sample from a copper processing plant in the following way. He adds powdered iron to a 200.mL copper(II) sulfate sample from the plant until no more copper will precipitate. He then washes, dries, and weighs the precipitate, and finds that it has a mass of 95.mg

Calculate the original concentration of copper(II) sulfate in the sample. Round your answer to 2 significant digits.

<u>Answer:</u> The concentration of copper sulfate in the sample is 0.0075 M

<u>Explanation:</u>

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

$\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}$

Given mass of copper = 95 mg = 0.095 g (Conversion factor: 1 g = 1000 mg)

Molar mass of copper = 63.55 g/mol

Putting values in above equation, we get:

$\text{Moles of copper}=\frac{0.095g}{63.55g/mol}=0.0015mol$

The given chemical equation follows:

$Fe(s)+CuSO_4(aq.)\rightarrow Cu(s)+FeSO_4(aq.)$

By Stoichiometry of the reaction:

1 mole of copper is formed by 1 mole of copper sulfate

So, 0.0015 moles of copper will be formed by = $\frac{1}{1}\times 0.0015mol=0.0015mol$ of copper sulfate

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

$\text{Molarity of the solution}=\frac{\text{Moles of solute}\times 1000}{\text{Volume of solution (in mL)}}$

Moles of copper sulfate = 0.0015 moles

Volume of solution = 200 mL

Putting values in above equation, we get:

$\text{Molarity of the solution}=\frac{0.0015\times 1000}{200}=0.0075M$

Hence, the concentration of copper sulfate in the sample is 0.0075 M

7 0

3 years ago

Help? how can i do this?

lubasha [3.4K]

882µg x 1g/10^6µg = 8.82 x 10^-4 g

use the conversion factor 1µg = 10^-6m

8.82 x 10^-4g

7 0

3 years ago

AgNO3(aq)+Na3PO4(aq) ionic equation

Leno4ka [110]

All species are "(aq)" unless marked otherwise:

molecular: Na3PO4 + 3 AgNO3 → Ag3PO4(s) + 3 NaNO3
total ionic: 3 Na{+} + PO4{3-} + 3 Ag{+} + 3 NO3{-} → Ag3PO4(s) + 3 Na{+} + 3 NO3{-}
net ionic: PO4{3-} + 3 Ag{+} → Ag3PO4(s)

K2SO4(aq)+Na2CO3(aq) no reaction

molecular: Pb(NO3)2 + Na2CO3 → PbCO3(s) + 2 NaNO3
total ionic: Pb{2+} + 2 NO3{-} + 2 Na{+} + CO3{2-} → PbCO3(s) + 2 Na{+} + 2 NO3{-}
net ionic: Pb{2+} + CO3{2-} → PbCO3(s)

molecular: BaCl2 + 2 KOH → Ba(OH)2(s) + 2 KCl
total ionic: Ba{2+} + 2 Cl{-} + 2 K{+} + 2 OH{-} → Ba(OH)2(s) + 2 K{+} + 2 Cl{-}
net ionic: Ba{2+} + 2 OH{-} → Ba(OH)2(s)

5 0

3 years ago

Read 2 more answers

Which reaction is endothermic

anyanavicka [17]

The second one is endothermic as endothermic reactions require energy for the reaction to take place.

4 0

4 years ago

Someone please help will mark as brainliest

Bas_tet [7]

Answer:

4. A subscript is a sentence below a line. You cannot change subscripts in a chemical formula to balance a chemical equation

5. where's/whats the equation??

6. ^^^

Explanation:

7 0

3 years ago