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4 years ago

The number of protons plus neutrons in the atom is called its?

Chemistry

2 answers:

Olegator [25]4 years ago

7 0

The mass number is protons plus neutrons

yKpoI14uk [10]4 years ago

5 0

This is the thing called the mass number of the thing

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How many molecules of calcium chloride are in 3CaCl2

Soloha48 [4]

3*40+3*2*35.5=333* Avogadro’s number =
1.98*10^25

8 0

3 years ago

Please somebody help!!!!!!!!!!!!!

natta225 [31]

Answer:

1.Materials

2. Hypothesis

3.Question

4.Procedure

5.Further questions

6.Results and Data

7.Conclusion

Explanation:

4 0

3 years ago

What is the hybridization and shape for an XeF6 2+ molecule?

Anna11 [10]

Answer:

Xe:[Kr]4d¹⁰5(sp³d³)₆⁺² => Octahedral Geometry (AX₆)⁺²

Explanation:

Xe:[Kr]4d¹⁰(5s²5p₋₁²p₀²p₁²5d₋₂d₋₁d₀)⁺² => Xe[Kr]5(sp³d³)₆²

Ca. #Valence e⁻ = Xe + 6F - 2e⁻ = 1(8) + 6(7) - 2 = 48

Ca. #Substrate e⁻ = 6F = 6(8) = 48

#Nonbonded free pairs e⁻ = (V - S)/2 = (48 - 48)/2 = 0 free pairs

#Bonded pairs e⁻ = 6F substrates = 6 bonded pairs

BPr + NBPr = 6 + 0 = 6 e⁻ pairs => Geometry => [AX₆]⁺² => Octahedron

Xe:[Kr]4d¹⁰(5s²5p₋₁²p₀²p₁²5d₋₂d₋₁d₀)⁺² => Xe[Kr]5(sp³d³)₆⁺²

XeF₆⁺² => 6(sp³d³) hybrid orbitals => Octahedral Geometry (AX₆)

8 0

3 years ago

Consider the following reaction: 2CH3OH(g)  2CH4(g) + O2(g) ΔH = +252.8 kJ a) Calculate the amount of heat transferred when 24.

denpristay [2]

Answer:

For a: The amount of heat transferred for the given amount of methanol is 94.6736 kJ.

For b: The mass of methane gas produced will be 10.384 g.

Explanation:

For the given chemical reaction:

$2CH_3OH(g)\rightarrow 2CH_4(g)+O_2(g);\Delta H=+252.8kJ$

For a:

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

$\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}$ ......(1)

Given mass of methanol = 24.0 g

Molar mass of methanol = 32.04 g/mol

Putting values in above equation, we get:

$\text{Moles of methanol}=\frac{24.0g}{32.04g/mol}=0.749mol$

By Stoichiometry of the reaction:

For every 2 moles of methanol, the amount of heat transferred is +252.8 kJ.

So, for every 0.749 moles of methanol, the amount of heat transferred will be = $\frac{252.8}{2}\times 0.749=94.6736kJ$

Hence, the amount of heat transferred for the given amount of methanol is 94.6736 kJ.

For b:

By Stoichiometry of the reaction:

252.8 kJ of energy is absorbed when 2 moles of methane gas is produced.

So, 82.1 kJ of energy will be absorbed when = $\frac{2}{252.8}\times 82.1=0.649mol$ of methane gas is produced.

Now, calculating the mass of methane gas from equation 1, we get:

Molar mass of methane gas = 16 g/mol

Moles of methane gas = 0.649 moles

Putting values in equation 1, we get:

$0.649mol=\frac{\text{Mass of methane gas}}{16g/mol}\\\\\text{Mass of methane}=10.384g$

Hence, the mass of methane gas produced will be 10.384 g.

7 0

3 years ago

A 25 mL sample of 0.100 M HNO3 completely reacts with NaOH according to this equation:

Anastasy [175]

It is a good thing that you already have answered the first question. Now, moving on to the second question, there exist an equation for the neutralization of acid by a base that is shown below,
M₁V₁ = M₂V₂
Now, all the variables in the equation are given except for our unknown which is the V₂. Substituting the known values from the given above,
(0.1 M)(25 mL) = (0.05 M)(V₂)
The value of V₂ from the equation above is 50 mL. Therefore, 50 mL of 0.05 M NaOH solution will be needed to completely react with HNO3.

6 0

3 years ago

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