1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Andre45 [30]
3 years ago
11

PLS HELP.

Chemistry
1 answer:
Lesechka [4]3 years ago
6 0

Answer:

1. 57.5%

2. 27.89 g

Explanation:

1. Determination of the percentage of sodium in sodium hydroxide.

Molar mass of NaOH = 23 + 16 + 1 = 40 g/mol

Mass of Na in NaOH = 23 g

Percentage of Na = mass of Na / Molar mass of NaOH × 100

Percentage of Na = 23/40 × 100

Percentage of Na = 57.5%

2. Determination of the mass of sodium in 48.5 g of sodium hydroxide.

Molar mass of NaOH = 23 + 16 + 1 = 40 g/mol

Mass of Na in NaOH = 23 g

Total mass of NaOH = 48.5 g

Mass composition of Na = mass of Na / Molar mass of NaOH × Total mass

Mass composition of Na = 23/40 × 48.5

Mass composition of Na = 27.89 g

You might be interested in
A mixture is made of two or more materials that A. cannot be separated by any means. B. cannot be separated by physical means. C
jekas [21]

The answer would be option D. can only be seperated by chemical means

5 0
3 years ago
Read 2 more answers
Question 8 (1 point)
Margaret [11]

Combustion of Fossil Fuels

Explanation:

The combustion of fossil fuels is a major contributor to unbalancing of the carbon cycle which causes more carbon dioxide to be released into the air than can be naturally processed.

Combustion of fossil fuel is an anthropogenic source of carbon dioxide emission. This chemical process is used to power internal combustion engines and industrial activities. The by product is usually carbon dioxide.

Plants that use carbon dioxide for their life processes cannot completely absorb all of this anthropogenic emission.

Naturally, animal respiration and decomposition provides enough carbon dioxide for use during photosynthesis. Combustion of fossil fuels tips this balance.

Learn more:

Energy brainly.com/question/9231468

#learnwithBrainly

5 0
3 years ago
A mixture containing nitrogen and hydrogen weighs 3.49 g and occupies a volume of 7.45 L at 305 K and 1.03 atm. Calculate the ma
-BARSIC- [3]

Answer:

Mass percent N₂ = 89%

Mass percent H₂ = 11%

Explanation:

First we <u>use PV=nRT to calculate n</u>, which is the total number of moles of nitrogen and hydrogen:

  • 1.03 atm * 7.45 L = n * 0.082 atm·L·mol⁻¹·K⁻¹ * 305 K
  • n = 0.307 mol

So now we know that

  • MolH₂ + MolN₂ = 0.307 mol

and

  • MolH₂ * 2 g/mol + MolN₂ * 28 g/mol = 3.49 g

So we have a <u>system of two equations and two unknowns</u>. We use algebra to solve it:

Express MolH₂ in terms of MolN₂:

  • MolH₂ + MolN₂ = 0.307 mol
  • MolH₂ = 0.307 - MolN₂

Replace that value in the second equation:

  • MolH₂ * 2 g/mol + MolN₂ * 28 g/mol = 3.49
  • (0.307-MolN₂) * 2 + MolN₂ * 28 = 3.49
  • 0.614 - 2MolN₂ + 28molN₂ = 3.49
  • 0.614 + 26MolN₂ = 3.49
  • MolN₂ = 0.111 mol

Now we calculate MolH₂:

  • MolH₂ + MolN₂ = 0.307 mol
  • MolH₂ + 0.111 = 0.307
  • MolH₂ = 0.196 mol

Finally, we convert each of those mol numbers to mass, to <u>calculate the mass percent</u>:

  • N₂ ⇒ 0.111 mol * 28 g/mol = 3.108 g N₂
  • H₂ ⇒ 0.196 mol * 2 g/mol = 0.392 g H₂

Mass % N₂ = 3.108/3.49 * 100% = 89.05% ≅ 89%

Mass % H₂ = 0.392/3.49 * 100% = 11.15% ≅ 11%

5 0
3 years ago
D is a green crystalline solid that dissolves in water to give a very pale green solution addition of sodium hydroxide solution
Ksivusya [100]

Answer:

I think its iron(II) oxide

Explanation:

The substance is black but when it's mixed with water it turns green solution so when mixed with sodium Hydroxide it turns green

5 0
3 years ago
About how long is 1 meter?
lyudmila [28]
It should be 3 feet... I did something like this one day in school but I’m trying to remember
3 0
3 years ago
Read 2 more answers
Other questions:
  • All of the following are examples of carbohydrates except fiber. proteins. starches. sugars.
    9·2 answers
  • Which term describes technology that operates on an atomic level
    7·2 answers
  • Define saturated solution. what happens as a saturated solution cools
    9·1 answer
  • A sample of ethane (C2H6)was combusted completely and the water that formed has a mass of 1.61 grams.How much ethane, in grams,
    10·1 answer
  • What is the mass of 6.00 cm^3 of mercury, density = 13.5939 g/cm^3?
    12·1 answer
  • What can destroy buffer solution?
    13·1 answer
  • Determine the number of molecules present in 5.60 mol of nitrogen dioxide, the number of atoms of oxygen, and the number of nitr
    6·1 answer
  • What is the pH of a buffer that is 0.100 M methylamine and 0.175 M methylammonium chloride at 25 °C? pkb for methylamine = 3.36
    10·1 answer
  • In order for sodium to have 8 valence electrons it would need to either gain _____ electrons or lose _____ electron.
    8·1 answer
  • Please help Please Help
    8·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!