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3 years ago

How many moles of HF acid are there in an 80g sample?

1 answer:

5 0

Answer:
3.98 mol

Solution:
Moles and mass is related to each other as follow,

Moles = Mass / M.mass ------ (1)

Data Given:
Mole = ?

Mass = 80 g

M.mass = 20.07 g/mol ∴ (H = 1.08 g/mol) + (F = 18.99 g/mol)

Putting values in equation 1,

Mole = 80 g ÷ 20.07 g.mol⁻¹

Mole = 3.98 mol

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Why are salt and sugar both able to dissolve in water, even though the solutes have different types of chemical bonding?

Feliz [49]

Answer:

See explanation

Explanation:

A substance is only soluble in water if it is composed of ions or polar groups which are capable of interaction with water.

Salt is composed of ions which are easily solvated by the dipoles of water molecule. Sucrose is composed of polar groups capable of interaction with water. This accounts for the solubility of sucrose (sugar) in water. Sugar is a covalent molecule but is composed of polar groups while salt is composed of ionic bonds.

Hence salt and sugar are both soluble in water for the reasons described above.

4 0

3 years ago

Read 2 more answers

Turn the word equation into a chemical balanced equation.

yan [13]

(2)KClO3 = (2)KCl + (3)O2

you have 2 Potassium Chlorates for every 2 Potassium Chlorides and 3 Oxygen

7 0

3 years ago

For an aqueous solution of sodium chloride (NaCl) .Determine the molarity of 3.45L of a solution that contains 145g of sodium

worty [1.4K]

Molar mass NaCl = 58.44 g/mol

number of moles:

mass NaCl / molar mass

145 / 58.44 => 2.4811 moles of NaCl

Volume = 3.45 L

Therefore :

M = moles / volume in liters:

M = 2.4811 / 3.45

M = 0.719 mol/L⁻¹

hope this helps!

6 0

3 years ago

What is the molarity of a solution that contains 4.87 g KCI (74.55 g/mol) dissolved in in 500.0 ml water?

lbvjy [14]

Answer:

Molarity = 0.13M

Explanation:

n=m/M = 4.87/74.55= 0.065mol, V= 500ml= 0.5dm3

Applying

n= C×V

0.065= C×0.5

C= 0.13M

8 0

3 years ago

Read 2 more answers

Atoms are spherical in shape. Therefore, the Pt atoms in the cube cannot fill all the available space. If only 74.0 percent of t

charle [14.2K]

Answer:

A)6.6×10^22atoms of Pt in the cube

B)1.4×10^-8m

Explanation:

(a) Calculate the number of Pt atoms in the cube.

an edge length of platinum (Pt) = 1.0 cm.

Then Volume= 1.0 cm×1.0 cm×1.0 cm=1cm^3

Then we have volume of the cube as 1cm^3

Given:

The density Pt = 21.45 g/cm3

the mass of a single Pt atom =3.240 x 10^-22 g

Then with 1atom of the platinum element, we can calculate the number of Pt atoms in the cube as

Density of pt/mass of a single Pt atom

=(21.45 /=3.240 x 10^-22)

=6.6×10^22atoms of Pt in the cube

B)Volume of cube V=4/3πr^3

V= 4/3 ×π×r^3

V= 4.19067r^3

r^3= V/4.19067

But volume is not total volume but just 74% of it, then With 74% of the space inside the cube is taken up by Pt atoms, then we need to find 74% of volume of the cube which is 1cm^3

74/100 ×1= 0.74cm^3

Then our new volume V is 0.74cm^3

r^3=0.74/4.19067×6.620 x 10^22

r^3=2.6674×10^-24

r= 3√2.6674×10^-24

r=1.4×10^-8m

8 0

2 years ago