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3 years ago

Magnesium (Mg) has an atomic number of 12. What is the ground-state electron configuration of magnesium?

Chemistry

2 answers:

devlian [24]3 years ago

7 0

The answer is 1s22s22p63s2

Brums [2.3K]3 years ago

4 0

C. 12222632

You have to follow the Aufbau principle, which states that electrons populate the atomic orbitals situated at the lowest energy first.

The orbitals are:

333

4444

5555

666

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What particle has a positive electrical charge and is found in the nucleus?

Virty [35]

Electron is the answer

4 0

2 years ago

Read 2 more answers

For the following balanced equation: 3 Cu(s) + 8 HNO3(aq) → 3 Cu(NO3)2(aq) + 2 NO(g) + 4 H2O(l) a) How many moles of HNO3 will r

s344n2d4d5 [400]

Answer:

a) 26.67 moles HNO3

b) 0.33 moles NO

c) 0.40 moles NO is produced

d).157 moles Cu

e) 0.105 moles NO

f) 26.4 grams HNO3

g) Cu is in excess

h) 2.41 grams Cu remain

i) 2.37 grams NO

Explanation:

Step 1: Data given

Molar mass of Cu = 63.55 g/mol

Molar mass of HNO3 = 63.01 g/mol

Molar mass of Cu(NO3)2 = 187.56 g/mol

Molar mass of NO = 30.01 g/mol

Molar mass of H2O = 18.02 g/mol

Step 2: The balanced equation

3 Cu(s) + 8 HNO3(aq) → 3 Cu(NO3)2(aq) + 2 NO(g) + 4 H2O(l)

a) How many moles of HNO3 will react with 10 moles of Cu?

For 3 moles Cu we need 8 moles HNO3 to produce 3 moles Cu(NO3)2, 2 moles NO and 4 moles H2O

For 10 moles Cu we need 8/3 *10 = 26.67 moles HNO3

b) How many moles of NO will form if 0.50 moles of Cu reacts?

For 3 moles Cu we need 8 moles HNO3 to produce 3 moles Cu(NO3)2, 2 moles NO and 4 moles H2O

For 0.50 moles Cu we'll have 2/3 *0.50 = 0.33 moles NO

c) If 0.80 moles of H2O forms, how much NO must also form?

For 3 moles Cu we need 8 moles HNO3 to produce 3 moles Cu(NO3)2, 2 moles NO and 4 moles H2O

If 0.80 moles H2O is produced, 0.80/2 = 0.40 moles NO is produced

d) How many moles of Cu are in 10.0 grams of Cu?

Moles Cu = 10.0 grams / 63.55 g/mol = 0.157 moles

In 10.0 grams Cu we have 0.157 moles Cu

e) If 10.0 g of Cu reacts, how many moles of NO will form?

10.0 grams Cu = 0.157 moles

For 3 moles Cu we need 8 moles HNO3 to produce 3 moles Cu(NO3)2, 2 moles NO and 4 moles H2O

For 0.157 moles Cu we'll have 2/3 * 0.157 = 0.105 moles NO

f) If 10.0 g of Cu reacts, how many grams of HNO3 are required?

10.0 grams Cu = 0.157 moles

For 3 moles Cu we need 8 moles HNO3 to produce 3 moles Cu(NO3)2, 2 moles NO and 4 moles H2O

For 0.157 moles Cu we'll need 0.419 moles HNO3

This is 0.419 moles * 63.01 g/mol = 26.4 grams HNO3

g) If 10.0 g of Cu and 20.0 g of HNO3 are put together in a reaction vessel, which one will be in excess?

Moles Cu = 0.157 moles

Moles HNO3 = 20.0 grams / 63.01 g/mo = 0.317 moles

For 3 moles Cu we need 8 moles HNO3 to produce 3 moles Cu(NO3)2, 2 moles NO and 4 moles H2O

The limiting reactant is HNO3. It will completely be consumed (0.317 moles). Cu is in excess. There will react 3/8 * 0.317 = 0.119 moles Cu

There will remain 0.157 - 0.119 = 0.038 moles

h) How many grams of the excess substance will be left over?

There will react 3/8 * 0.317 = 0.119 moles Cu

There will remain 0.157 - 0.119 = 0.038 moles

This is 0.038 moles * 63.55 g/mol = 2.41 grams

i) How many grams of NO will form in the reaction described in part g?

For 3 moles Cu we need 8 moles HNO3 to produce 3 moles Cu(NO3)2, 2 moles NO and 4 moles H2O

For 0.317 moles HNO3 we'll have 0.317/4 = 0.0793 moles NO

This is 0.079 mol * 30.01 g/mol = 2.37 grams NO

3 0

3 years ago

If 115grams of a substance reacts with 84grams of another substance, what will be the mass of the products after the reaction?

AysviL [449]

Isn’t it 115+84 so 199

4 0

3 years ago

2.In a titration, 25.00 cm3 of a solution of hydrochloric acid reacted with 18.40 cm3 of sodium hydroxide solution of concentrat

telo118 [61]

Answer:

0.11mol/dm³

Explanation:

The reaction expression is given as:

HCl + NaOH → NaCl + H₂O

Volume of acid = 25cm³ = 0.025dm³

Volume of base = 18.4cm³ = 0.0184dm³

Concentration of base = 0.15mol/dm³

Solution:

The concentration of hydrochloric acid = ?

To solve this problem, let us first find the number of moles of the base;

Number of moles = concentration x volume

Number of moles = 0.15mol/dm³ x 0.0184dm³ = 0.00276mol

From the balanced reaction equation;

1 mole of NaOH will combine with 1 mole of HCl

Therefore, 0.00276mol of the base will combine with 0.00276mol of HCl

So;

Concentration of acid = $\frac{number of moles }{volume}$ = $\frac{ 0.00276}{0.025}$ = 0.11mol/dm³

4 0

3 years ago

What is the correct formula for Heptarsenic Tetrabromide

harina [27]

Hepta is seven and tetra is four, so option c is your answer

3 0

3 years ago