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.
Answer:

Explanation:
Hello there!
In this case, since we have a problem about volume-pressure relationship, the idea here is to use the Boyle's law to calculate the final volume as shown below:

Then, we plug in the initial and final pressures and the initial volume to obtain:

Regards!
Climate change from the use of metals i think sorry if i’m wrong that one seems the most ligit to me
The correct way to write this number in scientific notation : 6.022 x 10²³
<h3>Further explanation
</h3>
Scientific Notation is a standard form of writing numbers used in mathematical operations
The rules:
1. Writing order : first digit, decimal point, next digit
2. Then followed by powers of 10 (the value can be +/-)
If the value is> 10 (the power of 10 is +), the decimal point is moved to the left, to the right of the first digit
If the value is <10 ((the power of 10 is -), the decimal point is moved to the right, to the right of the first digit
I certainly didn't count the details of the number of zeros listed, but only saw the answer choices.
And the right ones are: 6.022 x 10²³