<h3>Answer:</h3>
Curium-247 <em>i.e.</em> ²⁴⁷₉₆Cm
<h3>Explanation:</h3>
Alpha decay is given by following general equation,
ᵃₓA → ⁴₂He + ᵃ⁻⁴ₓ₋₂B
Where;
A = Parent Isotope
B = Daughter Isotope
ᵃ = Mass Number
ₓ = Atomic Number
Californium-251 is the parent isotope in our case and it has 98 protons (atomic number) and is given as,
²⁵¹₉₈Cf
The alpha decay reaction of Californium-251 will be as,
²⁵¹₉₈Cf → ⁴₂He + ²⁴⁷₉₆B
The symbol for B with atomic number 96 was found to be the atom of Curium (Cm) by inspecting periodic table. Hence, the final equation is as follow,
²⁵¹₉₈Cf → ⁴₂He + ²⁴⁷₉₆Cm
All cells need oxygen in order to function
Answer:
Molarity of Na₂CO₃ = 0.25M
% mass = 2.69
Explanation:
Molarity means mole of solute in 1L of solution
Molar mass of solute (Na₂CO₃) = 105,98 g/m
Moles = mass / molar mass → 6.73 g / 105.98 g/m = 0.0635 m
Mol/L = [M]
0.0635 mol/0.250L = 0.25M
Density of solution = Solution mass / Solution volume
1 g/ml = Solution mass / 250 mL → Solution mass is 250g
% mass will be:
In 250 g of solution we have 6.73 g of solute
in 100 g of solution we have (100 . 6.73)/250 = 2.69
Answer:
1.195 M.
Explanation:
- We can calculate the concentration of the stock solution using the relation:
<em>M = (10Pd)/(molar mass).</em>
Where, M is the molarity of H₂SO₄.
P is the percent of H₂SO₄ (P = 40%).
d is the density of H₂SO₄ (d = 1.17 g/mL).
molar mass of H₂SO₄ = 98 g/mol.
∴ M of stock H₂SO₄ = (10Pd)/(molar mass) = (10)(40%)(1.17 g/mL) / (98 g/mol) = 4.78 M.
- We have the role that the no. of millimoles of a solution before dilution is equal to the no. of millimoles after dilution.
<em>∴ (MV) before dilution = (MV) after dilution</em>
M before dilution = 4.78 M, V before dilution = 250 mL.
M after dilution = ??? M, V after dilution = 1.0 L = 1000 mL.
∴ M after dilution = (MV) before dilution/(V after dilution) = (4.78 M)(250 mL)/(1000 mL) = 1.195 M.
