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3 years ago

How many moles are in 45.8 g of calcium nitrate, Ca(NO3),?

Chemistry

1 answer:

Deffense [45]3 years ago

4 0

Answer:

the number of moles is 0.279

Explanation:

The calculation of the number of moles of calcium nitrate, is given below;

As We know that

Number of moles = mass of substance ÷ molecular weight

where

Mass of substance is 45.8g

And, the molecular weight is 164.088

so,

= 45.8 g ÷ 164.088

= 0.279moles

Thus , the number of moles is 0.279

We simply used the above formula so that the accurate value could arrive

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Consider the reaction below for which K = 78.2 atm-1. A(g) + B(g) ↔ C(g) Assume that 0.386 mol C(g) is placed in the cylinder re

borishaifa [10]

Answer:

1.65 L

Explanation:

The equation for the reaction is given as:

A + B ⇄ C

where;

numbers of moles = 0.386 mol C (g)

Volume = 7.29 L

Molar concentration of C = $\frac{0.386}{7.29}$

= 0.053 M

A + B ⇄ C

Initial 0 0 0.530

Change +x +x - x

Equilibrium x x (0.0530 - x)

$K = \frac{[C]}{[A][B]}$

where

K is given as ; 78.2 atm-1.

So, we have:

$78.2=\frac{[0.0530-x]}{[x][x]}$

$78.2= \frac{(0.0530-x)}{(x^2)}$

$78.2x^2= 0.0530-x$

$78.2x^2+x-0.0530=0$

Using quadratic formula;

$\frac{-b+/-\sqrt{b^2-4ac} }{2a}$

where; a = 78.2 ; b = 1 ; c= - 0.0530

= $\frac{-b+\sqrt{b^2-4ac} }{2a}$ or $\frac{-b-\sqrt{b^2-4ac} }{2a}$

= $\frac{-(1)+\sqrt{(1)^2-4(78.2)(-0.0530)} }{2(78.2)}$ or $\frac{-(1)-\sqrt{(1)^2-4(78.2)(-0.0530)} }{2(78.2)}$

= 0.0204 or -0.0332

Going by the positive value; we have:

x = 0.0204

[A] = 0.0204

[B] = 0.0204

[C] = 0.0530 - x

= 0.0530 - 0.0204

= 0.0326

Total number of moles at equilibrium = 0.0204 + 0.0204 + 0.0326

= 0.0734

Finally, we can calculate the volume of the cylinder at equilibrium using the ideal gas; PV =nRT

if we make V the subject of the formula; we have:

$V = \frac{nRT}{P}$

where;

P (pressure) = 1 atm

n (number of moles) = 0.0734 mole

R (rate constant) = 0.0821 L-atm/mol-K

T = 273.15 K (fixed constant temperature )

V (volume) = ???

$V=\frac{(0.0734*0.0821*273.15)}{(1.00)}$

V = 1.64604

V ≅ 1.65 L

3 0

3 years ago

This figure (Figure 1)shows a container that is sealed at the top

guajiro [1.7K]

I'm pretty sure the answer is 0.833 atm.

Hope I helped! <3

-cara

7 0

3 years ago

How do you know if a compound will dissociate or ionize in water?

Ivenika [448]

when an ionic or covalent compound is dissolved in water they break apart into ions through process called dissociation ..the ions get attracted by the water molecules and hence they carry polar charges ..and if there is a conduction of electricity. .then we get to know that a compound is dissociated ..

HOPE IT IS HELPFUL

4 0

3 years ago

explain why it is a common laboratory procedure to heat analytical reagents and store them in a dessicated atmosphere (a sealed

Readme [11.4K]

Explanation:

Most reagent forms are going to absorb water from the air; they're called "hygroscopic". Water presence can have a drastic impact on the experiment being performed For fact, it increases the reagent's molecular weight, meaning that anything involving a very specific molarity (the amount of molecules in the final solution) will not function properly.

Heating will help to eliminate water, although some chemicals don't react well to heat, so it shouldn't be used for all. A dessicated environment is simply a means to "dry." That allows the reagent with little water in the air to attach with.

6 0

3 years ago

group of atoms that gains or loses electrons is called _______. A. a polar ion B. a non-polar ion C. a polyatomic ion D. a commo

raketka [301]

Answer: Option (C) is the correct answer.

Explanation:

An ion is defined as a specie which is formed when a neutral atoms tends to gain or lose an electron.

When a neutral atom gain an electron then it forms a negative ion whereas when a neutral atom tends to lose an electron then it forms a positive ion.

For example, a neutral fluorine atom on gaining an electron will form $F^{-}$ ion. And, a sodium atom on losing an electron forms $Na^{+}$ ion.

When a group of atoms form ions then it tends to form polyatomic ions.

Thus, we can conclude that group of atoms that gains or loses electrons is called a polyatomic ion.

7 0

3 years ago