contains polar bonds. D
and please help me with my assignment and thanxs:)
Answer:
- The molarity of the student's sodium hydroxide solution is 0.0219 M
Explanation:
<u>1) Chemical reaction.</u>
a) Kind of reaction: neutralization
b) General form: acid + base → salt + water
c) Word equation:
- sodium hydroxide + oxalic acid → sodium oxalate + water
d) Chemical equation:
- NaOH + H₂C₂O₄ → Na₂C₂O₄ + H₂O
b) Balanced chemical equation:
- 2NaOH + H₂C₂O₄ → Na₂C₂O₄ + 2H₂O
<u>2) Mole ratio</u>
- 2mol Na OH : 1 mol H₂C₂O₄ :1 mol Na₂C₂O₄ : 2 mol H₂O
<u>3) Starting amount of oxalic acid</u>
- mass = 28 mg = 0.028 g
- molar mass = 90.03 g/mol
- Convert mass in grams to number of moles, n:
n = mass in grams / molar mass = 0.028 g / 90.03 g/mol = 0.000311 mol
<u>4) Titration</u>
- Volume of base: 28.4 mL = 0.0248 liter
- Concentration of base: x (unknwon)
- Number of moles of acid: 2.52 mol (calculated above)
- Proportion using the theoretical mole ratio (2mol Na OH : 1 mol H₂C₂O₄)
That means that there are 0.000622 moles of NaOH (solute)
<u>5) Molarity of NaOH solution</u>
- M = n / V (liter) = 0.000622 mol / 0.0284 liter = 0.0219 M
That is the correct number using <em>three signficant figures</em>, such as the starting data are reported.
Domain
Kingdom
Phylum
Class
Order
Family
Genus
Species
Answer:
1.076 mol (corrected to 2 d.p.)
Explanation:
Take the atomic mass of Ga be 69.7.
since no. of moles = mass/ molar mass,
no. of moles of Ga used = 100.0 / 69.7
= 1.43472023 mol
From the balanced equation, the mole ratio of Ga:S2 = 4:3, which means every 4 moles of Ga can react completely with 3 moles of S2.
So, let the no. of moles of Sulphur required be y.
4 y = 1.43472023 x 3
y = 1.076 mol (corrected to 2 d.p.)
Answer:
convection
Explanation:
as air is heated, it rises up and away from the heat source, cools then falls closer to the heat source over and over again.