Answer:
1. Theoretical yield = 2.03g
2. Actual yield 1.89g
Explanation:
Let us write a balanced equation. This is illustrated below:
Zn + 2HCI —> ZnCl2 + H2
Molar Mass of HCl = 1 +35.5 = 36.5g/mol
Mass of HCl from the balanced equation = 2 x 36.5 = 73g
Molar Mass of H2 = 2x1 = 2g/mol
1. From the equation,
73g of HCl produced 2g of H2.
Therefore, 74g of HCl will produce = (74 x 2)/73 = 2.03g
Therefore, theoretical yield = 2.03g
2. %yield = 93%
Theoretical yield = 2.03g
Actual yield =?
%yield = Actual yield /Theoretical yield x100
Actual yield = %yield x theoretical yield
Actual yield = 93% x 2.03 = (93/100)x2.03 = 1.89g
Actual yield =1.89g
Assume 1 tsp is approximately can hold 5 mL liquid.
Given the dose of medicine = 1.5 tsp
Converting 1.5 tsp to mL:
= 7.5 mL
Given the specific gravity of the medicine = 1.23
That means density of the medicine with respect to water will be 1.23
As the density of water is 1 g/mL
We can take density of the medicine to be 1.23 g/mL
Calculating the mass of medicine in grams:

9.225 g medicine is present in one dose.
The answer is the last one, “The cell membrane is the only source of support and structure in plant and animal cells.” That is false because plant cells have a cell wall and cell membrane while animal cells only have a cell membrane.
Hope this helps:)
The number of oxygen atoms are 6 atoms
<u><em>Explanation</em></u>
According to the law of mass conservation the number of reactant atoms is equal to number of product atoms.
For given equation to obey the law of mass conservation it need to be balanced as below
4 Al + 3 O₂ → 2 Al₂O₃
Al₂O₃ is the product,therefore the number of oxygen atom
= coefficient in front of Al₂O₃ × subscript of O
=2 x 3 = 6 atoms
Answer: 
Explanation:
Firstly, we have to find the Molecular mass of potassium oxide (
):
atomic mass: 39 u
atomic mass: 16 u
molecular mass: 
This means that in 1 mole of
there are
and we need to find how many moles there are in
:
1 mole of
-----
of 
-----
of 

This is the quantity of moles in 73.9 g of potassium oxide
Now we can calculate the number of atoms in 73.9 g of potassium oxide by the following relation:

Where:
is the number of atoms in 73.9g of potassium oxide
is the Avogadro's number, which is determined by the number of particles (or atoms) in a mole.
Then:

This is the quantity of atoms in 73.9g of potassium oxide