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3 years ago

What is a pure substance - bread, salt, seawater, or soil?

2 answers:

7 0

Answer: Salt is a pure substance. Pure substances are composed of one type of molecule. All of the substances listed are composed of two or more types of molecules, except for salt. Therefore, salt would be your answer.

Hope this helps.

miv72 [106K]3 years ago

5 0

Answer:

Salt is the pure substance out of them all.

You might be interested in

List the 3 ways carbon can enter the ocean?

prohojiy [21]

Carbon dioxide from the atmosphere dissolves in the surface waters of the ocean. Some of the carbon dioxide stays as dissolved gas, but much of it gets turned into other things. Photosynthesis by tiny marine plants (phytoplankton) in the sunlit surface waters turns the carbon into organic matte

6 0

3 years ago

How many moles of Manganese there in are 5.76 x 10(15) atoms of Mn?

aksik [14]

Answer:

1. 9.57 × 10^-9 moles.

2. 7.38mol

Explanation:

1.) To find the number of moles there are in the number of particles in an atom, we divide the number of particles (nA) by Avagadro's constant (6.02 × 10^23)

Hence, to find the number of moles (n) of Manganese (Mn), we say:

5.76 x 10^15 atoms ÷ 6.02 × 10^23

5.76/6.02 × 10^(15-23)

= 0.957 × 10^-8

= 9.57 × 10^-9 moles.

2.) Mole = mass/molar mass

Molar mass of sodium chloride (NaCl) = 23 + 35.5

= 58.5g/mol

mole = 431.6 g ÷ 58.5g/mol

mole = 7.38mol

7 0

3 years ago

To determine the ammonia concentration in a sample of lake water, three samples are prepared. In sample A, 10.0 mL of lake water

Masteriza [31]

Answer:Sample Absorbance (625 nm)

A 0.536

B 0.783

C 0.045

Therefore, I will use these data to solve your question. If you have other absorbances values, just follow my steps and plug in different numbers.

First, we see 1 mole of NH3 gives 1 mole product.

In B moles of NH3 = moles of NH3 in A + (5.5 x10^-4 x2.5/1000) = 1.375 x10^6 + mA

( mA = moles of NH3 in A) vol of B = 25 = vol of A

now A = el C = eC ( since l = 1cm)

Because, n net absorbance due to complex blank absorbance must be removed.

Here A(A) = 0.536 - 0.045 = 0.491 , A(B) = 0.783 - 0.045 = 0.738

(you can plug in different numbers in this step)

A2/A1 = C2/C1 , A(B)/A(A) = (1.375x10^-6 +mA)/(mA) = 0.738/0.491

So, mA = 2.733 x 10^-6 = moles of NH3 in A (Lake water)

Hence [NH3] water ( 2.733 x10^-6 ) x 1000/25 = 1.093 x 10^-4 M

Lake water vol = 10 ml out of 25,

Concentration of ammonia in lake water = 2.733 x10^-6 x 1000/10 = 2.733 x 10^-4 M

Then, A = 0.491 = e x 1 x 1.093 x10^-4

e = 4492 M-1cm-1

Explanation:

4 0

3 years ago

Natural remedies are usually more effective and safer because they have thoroughly tested .

mihalych1998 [28]

The answer for this question would be B) False or the second option.

Answer is FALSE: ✅

6 0

3 years ago

A cylinder is filled with 10.0L of gas and a piston is put into it. The initial pressure of the gas is measured to be 209.kPa. T

disa [49]

Answer : The final pressure of the gas will be, 26.8 kPa

Explanation :

According to the Boyle's law, the pressure of the gas is inversely proportional to the volume of the gas at constant temperature of the gas and the number of moles of gas.

$P\propto \frac{1}{V}$