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3 years ago

What is the mass number of sodium?

2 answers:

5 0

Answer: Since all sodium atoms have 11 protons, this one has 11 protons. This tells us that it also has 11 electrons. Since the mass number is 23, we know that the sum of protons and neutrons in the nucleus must equal 23.

So the answer is : Mass number = 23

Explanation:

Rina8888 [55]3 years ago

4 0

23 sowwy if im wrong 0_0

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If an unknown sample contains 39.04% sulfuric acid by mass, then a 0.9368 g of that sample would require _____ mL of 0.2389 M Na

bonufazy [111]

Answer:

A) 31.22

Explanation:

The reaction of sulfuric acid with NaOH is:

H₂SO₄ + 2 NaOH → Na₂SO₄ + 2H₂O

To solve this problem we need to determine the moles of acid that will react, and, using the chemical equation we can determine the moles of NaOH and the volume that a 0.2389M NaOH solution would require to neutralize it.

<em>Moles H₂SO₄ (Molar mass: 98.08g/mol):</em>

0.9368g * 39.04% = 0.3657g H₂SO₄ * (1mol / 98.08g) =

3.7289x10⁻³moles H₂SO₄

And moles of NaOH that you require to neutralize the acid are:

3.7289x10⁻³moles H₂SO₄ * (2 moles NaOH / 1 mole H₂SO₄) =

7.4578x10⁻³ moles NaOH

Using a 0.2389M NaOH solution:

7.4578x10⁻³ moles NaOH * (1L / 0.2389mol) = 0.03122L = 31.22mL

Right answer is:

5 0

3 years ago

What is the value of all conversion factors that are used in dimensional analysis

IRISSAK [1]

All the conversions have a net value of 1

4 0

2 years ago

Read 2 more answers

If you are given the molarity of a solution, what additional information would you need to find the weight/weight percent (w/w%)

Ludmilka [50]

Answer:

- The molar mass of the solute, in order to convert from moles of solute to grams of solute.

- The density of solution, to convert from volume of solution to mass of solution.

Explanation:

Hello,

In this case, since molarity is mathematically defined as the moles of solute divided by the volume of solution and the weight/weight percent as the mass of solute divided by the mass of solution, we need:

- The molar mass of the solute, in order to convert from moles of solute to grams of solute.

- The density of solution, to convert from volume of solution to mass of solution.

For instance, if a 1-M solution of HCl has a density of 1.125 g/mL, we can compute the w/w% as follows:

$w/w\%=1\frac{molHCl}{L\ sln}*\frac{36.45gHCl}{1molHCl}*\frac{1L\ sln}{1000mL\ sln}*\frac{1mL\ sln}{1.125g\ sln} *100\%\\\\w/w\%=3.15\%$

Whereas the first factor corresponds to the molar mass of HCl, the second one the conversion from L to mL of solution and the third one the density to express in terms of grams of solution.

Regards.

4 0

2 years ago

The conversion of co2 and h2o into organic compounds using energy from light is called

Fed [463]

The answer you're looking for is photosynthesis

3 0

3 years ago

A high speed train travels 176 miles in 7 hours. What is the speed of the train

umka21 [38]

Answer:

25 mph

Explanation:

So we have to find the unit rate, or you could use the DTS triangle, but both say you have to divide, so our equation is:

176 ÷ 7 = 25.14

But I'm going to round that

So the train is traveling at 25 mph

hope this helps:/

4 0

2 years ago