Why do atoms receive a positive or negative charge when they give or take electrons? Include the nucleus in your
1 answer:
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Answer:
<h3>The answer is 0.75 g/mL</h3>Explanation:
The density of a substance can be found by using the formula
From the question
mass = 90 g
volume = 120 mL
We have
We have the final answer as
<h3>0.75 g/mL</h3>Hope this helps you
Answer:
a) LAW OF MULTIPLE PROPORTIONS
b) 0.095g, 0.71g, 0.285g respectively
c) X2Y, YZ15, X6Y
d) hence mass of compound X = 21 x 0.045 = 0.95g
mass of compound Y = 21 x 0.955 = 20.05g
Explanation:
a) The assumptions made in solving this questions is the application of the LAW OF MULTIPLE PROPORTIONS. The Law of multiple proportions states that if two elements A and B combine together to form more than one compound, then the several masses of A which chemically combine with a fixed mass of B is in a simple ratio.
for example, copper forms two oxides ; copper(I) oxide (CuO) and copper(ii) oxide(Cu2O), it is possible for the two samples of the oxides to be reduced to Cu by reacting with Hydrogen gas. as such, certain masses of oxygen combine separately with a fixed mass of Cu. then the ratios of Cu are then determined.
b) To calculate the relative masses, we take note of the three compounds given, they all have some amount of Y in them, hence we can use Y as our relative mass, this implies that the relative mass of Y = 1g
mass of X = 0.4g
mass of Y = 4.2g
amount of X in 1g of Y = 0.4 x 1 /4.2
= 0.095g
for compound 2;
mass of Y = 1.4g
mass of Z = 1.0g
amount of Z in 1g of Y =1.0 x 1 /1.4
= 0.71g
for compound 3;
mass of X = 2.0g
mass of Y = 7.0g
amount of X in 1g of Y = 1 x 2/7
= 0.285g
c) Applying the law of multiple proportions; since elements X and Z combine with a fixed mass of Y, they must bear a simple ratio;
compound 1/compound 3 = 0.095/0.285
= 1/3
compound 1/compound 2 = 0.095/0.71
= 2/15
compound 2/ compound 3 = 0.71/0.285
= 5/2
formular for compound 1 = X2Y
formula for compound 2 = YZ15
formular for compound 3 = X6Y
d) from the formular X2Y, we can get the amount of each product in XY using the ratios
%of compound XY in X = mass of compound X / total Mass
= 0.2/4.4 = 4.5%
as such in a 21g of compound XY, %of compound Y = 1 - %of compound X = 95.5%
hence mass of compound X = 21 x 0.045 = 0.95g
mass of compound Y = 21 x 0.955 = 20.05g
Answer:
Approximately formula units (
).
Explanation:
Refer to a modern periodic table for the relative atomic mass of magnesium () and chlorine (
):
:
.
:
.
In other words, the mass of of
atoms would be (approximately)
.
Likewise, the mass of of
atoms would be approximately
.
One formula unit of the ionic compound includes exactly as many atoms as there are in the given formula. The formula mass of a compound is the mass of
of the formula units of this compound.
The formula includes one
atom and two
atoms.
Hence, every formula unit of would include the same number of atoms: one
atom and two
atoms. There would be
of
atoms and
of
atoms in
of
formula units.
Thus, the mass of of
formula units would be equal to the mass of
of
atoms plus the mass of
of
atoms. (The mass of
of each atom could be found from the relative atomic mass of each element.)
.
In other words, the formula mass of is
.
Therefore, the number of formula units in of
would be:
.
Multiple by Avogadro's Number
to estimate the number of formula units in
:
.