Molar concentration is a measure of the concentration of a solute in a solution, or of any chemical species, in terms of amount of substance per unit volume.
<span>Answer:
pH = 2.7, therefore amount of H+ needed is 10^-2.7 M
u haf 80 ml of hcl and 90 ml of naoh left, therefore 20 ml of hcl used, and 10ml of naoh used.
mols of H+ = 0.02 x 7 x 10^-2 = 1.4 x 10^-3
mols of OH- = 0.01 x 5 x 10^-2 = 5 x 10^-4
H+ and OH- neutralise each other, so remaining mols of H+ = 9 x 10^-4
u need 10^-2.7 mols of H+, so 10^-2.7 - 9 x 10^-4 = 0.001095 mol
vol of HCL needed = 0.001095 / 7 x 10^-2 = 0.0156 L = 15.6 mL</span>
Answer:
the sodium nitrate in this investigation is
a) the solute
b) undergoing chemical change
<h3>
Explanation:</h3>
generally, solute is the substance which is added in solvent.
The substance which is taken in relatively more volume is the solvent.
so, here sodium nitrate (NaNO₃) is the solute which is dissolved in water (H₂O) , which is solvent.
The reaction between them is :
NaNO₃ + H₂O ⇒ Na⁺ (aq) + NO₃⁻ (aq) ; (aq) denotes aqueous;
so, here sodium nitrate undergoes chemical change into aqueous sodium ions(Na⁺) and aqueous nitrate ions(NO₃⁻).
<h3>
Answer:</h3>
Lead-205 (Pb-205)
<h3>
Explanation:</h3>
<u>We are given;</u>
We are supposed to identify its product after an alpha decay;
- Polonium-209 has a mass number of 209 and an atomic number of 84.
- When an element undergoes an alpha decay, the mass number decreases by 4 while the atomic number decreases by 2.
- Therefore, when Po-209 undergoes alpha decay it results to the formation of a product with a mass number of 205 and atomic number of 82.
- The product from this decay is Pb-205, because Pb-205 has a mass number of 205 and atomic number 82.
- The equation for the decay is;
²⁰⁹₈₄Po → ²⁰⁵₈₂Pb + ⁴₂He
- Note; An alpha particle is represented by a helium nucleus, ⁴₂He.
Answer:
4.8 mol
Step-by-step explanation:
The <em>balanced equation</em> is
Fe₂O₃ + Ca₃(PO₄)₂ ⟶2FePO₄ + 3CaO
You want to convert moles of Fe₂O₃ to moles of CaO.
The molar ratio is 3 mol CaO:1 mol Fe₂O₃.
Moles of CaO = 1.6 mol Fe₂O₃ × (3 mol CaO/1 mol Fe₂O₃)
Moles of CaO = 4.8 mol CaO
The reaction will produce 4.8 mol of CaO.