How many moles are equal to 89.23 g of calcium nitrate?

How many vance electrons does neon need to be stable

Aneli [31]

An element is stable when it has a full outershell.
Generally, most shells after the first can hold 8 electrons.
The first shell can only hold 2

So in order for neon to be stable it must have a full outer shell
The first shell can hold 2
Neon has 10 electrons
10-2=8
The second shell can hold 8
And neon has 8 electrons left

So it must have 8 valence electrons to be stable

8 0

3 years ago

True or false: scientists make observations very carefully science

Olenka [21]

True, scientists do make observations very carefully.

3 0

3 years ago

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In a combustion reaction, ethanol (C2H5OH) is burned in the presence of oxygen (O2), producing carbon dioxide (CO2) and water (H

charle [14.2K]

Answer:
Reactants: Ethanol (C₅H₅OH), Oxygen (O₂)

Products: Carbon dioxide (CO₂) and Water (H₂O)

Explanation:
Let’s rewrite each part of the described situation in chemical equation terms.

Ethanol - C₂H₅OH
is burned in the prescence of - +
oxygen - O₂
producing - →
carbon dioxide - CO₂
and - +
water - H₂O

Chemical equation:
C₂H₅OH + O₂ → CO₂ + H₂O

The terms on the left side of a chemical equation are reactants, and the terms on the right side of a chemical equation are products.

Therefore, since we know this, ethanol (C₂H₅OH) & oxygen (O₂) are the reactants, and carbon dioxide (CO₂) & water (H₂O) are the products.

8 0

3 years ago

What volume of nitrogen dioxide is formed at 735 torr and 28.2 °C by reacting 3.56 cm3 of copper (d = 8.95 g/cm3) with 200 mL of

weqwewe [10]

Answer:

25.76 L

Explanation:

Given, Volume of Copper = 3.56 cm³

Density = 8.95 g/cm³

Considering the expression for density as:

$Density=\frac {Mass}{Volume}$

So,

So, Mass= Density * Volume = 8.95 g/cm³ * 3.56 cm³ = 31.862 g

Mass of copper = 31.862 g

Molar mass of copper = 63.546 g/mol

The formula for the calculation of moles is shown below:

$moles = \frac{Mass\ taken}{Molar\ mass}$

Thus,

$Moles= \frac{31.862\ g}{63.546\ g/mol}$

Moles of copper = 0.5014 moles

Given, Volume of nitric acid solution = 200 mL = 200 cm³

Density = 1.42 g/cm³

Considering the expression for density as:

$Density=\frac {Mass}{Volume}$

So,

So, Mass= Density * Volume = 1.42 g/cm³ * 200 cm³ = 284 g

Also, Nitric acid is 68.0 % by mass. So,

Mass of nitric acid = $\frac {68}{100}\times 284\ g$ = 193.12 g

Molar mass of nitric acid = 63.01 g/mol

The formula for the calculation of moles is shown below:

$moles = \frac{Mass\ taken}{Molar\ mass}$

Thus,

$Moles= \frac{193.12\ g}{63.01\ g/mol}$

Moles of nitric acid = 3.0649 moles

According to the reaction,

$Cu_{(s)}+4HNO_3_{(aq)}\rightarrow Cu(NO_3)_2_{(aq)} + 2NO_2_{(g)} + 2H_2O_{(l)}$

1 mole of copper react with 4 moles of nitric acid

Thus,

0.5014 moles of copper react with 4*0.5014 moles of nitric acid

Moles of nitric acid required = 2.0056 moles

Available moles of nitric acid = 3.0649 moles

Limiting reagent is the one which is present in small amount. Thus, nitric acid is present in large amount, copper is the limiting reagent.

The formation of the product is governed by the limiting reagent. So,

1 mole of copper on reaction forms 2 moles of nitrogen dioxide

So,

0.5014 mole of copper on reaction forms 2*0.5014 moles of nitrogen dioxide

Moles of nitrogen dioxide = 1.0028 moles

Given:

Pressure = 735 torr

The conversion of P(torr) to P(atm) is shown below:

$P(torr)=\frac {1}{760}\times P(atm)$

So,

Pressure = 735 / 760 atm = 0.9632 atm

Temperature = 28.2 °C

The conversion of T( °C) to T(K) is shown below:

T(K) = T( °C) + 273.15

So,

T₁ = (28.2 + 273.15) K = 301.35 K

Using ideal gas equation as:

PV=nRT

where,

P is the pressure

V is the volume

n is the number of moles

T is the temperature

R is Gas constant having value = 0.0821 L.atm/K.mol

Applying the equation as:

0.9632 atm × V = 1.0028 mol × 0.0821 L.atm/K.mol × 301.35 K

⇒V = 25.76 L

4 0

3 years ago

I have an important test coming up!!! i need help with thisss!!!!

Aleks [24]

I think it’s A because each unit is worth 3

7 0

3 years ago

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