Easy stoichiometry conversion :)
So, for stoichiometry, we always start with our "given". In this case, it would be the 10.0 grams of NaHCO3. This unit always goes over 1.
So, our first step would look like this:
10.0
------
1
Next, we need to cancel out grams to get to moles. To do this, we will do grams of citric acid on the BOTTOM of the next step, so it cancels out. This unit in grams will be the mass of NaHCO3, which is 84.007. Then, we will do our unit of moles on top. Since this is unknown, it will be 1.
So, our 2nd step would look like this:
1 mole CO2
-----------------
84.007g NaHCO3
When we put it together: our complete stoichiometry problem would look like this:
10.0g NaHCO3 1mol CO2
---------------------- x -------------------------
1 84.007g NaHCO3
Now to find our answer, all we need to do is:
Multiply the two top numbers together (which is 10.0)
Multiply the two bottom numbers together (Which is 84.007)
And then....
Divide the top answer by the bottom answer.
10.0/84.007 is 0.119
So, from 10.0 grams of citric acid, we have 0.119 moles of CO2.
Hope I could help!
If the atom is neutral (meaning, not charged) the number of electron is equal to the number of protons. The mass number of an atom is the sum of the number of proton and the number of neutrons. From the given above, the mass number of gallium is 31 + 39. The answer is letter D. 70.
<h3>Answer:</h3>
7.57 × 10⁻²² g of F
<h3>Solution:</h3>
Data Given:
Number of Molecules = 8
M.Mass of BF₃ = 67.82 g.mol⁻¹
Mass of Fluorine atoms = ?
Step 1: Calculate Moles of BF₃
Moles = Number of Molecules ÷ 6.022 × 10²³ Molecules.mol⁻¹
Putting value,
Moles = 8 Molecules ÷ 6.022 × 10²³ Molecules.mol⁻¹
Moles = 1.33 × 10⁻²³ mol
Step 2: Calculate Mass of BF₃:
Moles = Mass ÷ M.Mass
Solving for Mass,
Mass = Moles × M.Mass
Putting values,
Mass = 1.33 × 10⁻²³ mol × 67.82 g.mol⁻¹
Mass = 9.0 × 10⁻²² g
Step 3: Calculate Mass of Fluorine Atoms:
As,
67.82 g BF₃ contains = 57 g of F
So,
9.0 × 10⁻²² g will contain = X g of F
Solving for X,
X = (9.0 × 10⁻²² g × 57 g) ÷ 67.82 g
X = 7.57 × 10⁻²² g of F
Answer:
1. is true
Explanation:
The solubility rules apply only to salts, which are ionic compounds.
2. is false. A strong electrolyte is a salt that dissociates completely in solution. Not all salts dissociate completely. For example, a 0.36 mol·L⁻¹ solution dissociates as:
K₂SO₄ ⟶ K⁺ + KSO₄⁻ (30 %) + SO₄²⁻
Thus, K₂SO₄ does not dissociate completely into K⁺ and SO₄²⁻ ions.
3. is false. The solubility rules apply only to aqueous solutions.
Answer:
240 mg
Explanation:
In a dilution, the total quantity of the solute remains equal, so the concentration multiplied by the volume, or mass, of it, must be constant. In this case, the concentration is measured by the mass (w/w), so:
C1M1 = C2M2
Where C is the concentration, M is the mass, 1 is the concentrated solution, and 2 the diluted. The powder mupirocin has 100% of concentration, and the diluted solution will be mass equal to 22 g plus the mass added, so:
100%*M1 = 3%*(22 + M1)
100M1 = 66 + 3M1
97M1 = 66
M1 = 0.6804 g
But the ointment already has 2% of mupirocin, which is in mass:
0.02* 22 = 0.44 g
So, the mass needed to be added is 0.6804 - 0.44 = 0.24 g = 240 mg
