How much of a 10 M solution is needed to make 1 liter of all solution?

Which subatomic particle of an atom never changes?

AlexFokin [52]

Protons are one of the fully stable parts of matter

8 0

3 years ago

Imagine you had HCl with a concentration of exactly 0.10 mol/dm3. If 0.023 dm3 of a sodium hydroxide solution, NaOH (aq), could

polet [3.4K]

Answer:

Explanation:

Step 1: Calculate the amount of sodium hydroxide in moles

Volume of sodium hydroxide solution = 25.0 ÷ 1,000 = 0.0250 dm3

Rearrange:

Concentration in mol/dm3 =

Amount of solutein mol = concentration in mol/dm3 × volume in dm3

Amount of sodium hydroxide = 0.100 × 0.0250

= 0.00250 mol

Step 2: Find the amount of hydrochloric acid in moles

The balanced equation is: NaOH(aq) + HCl(aq) → NaCl(aq) + H2O(l)

So the mole ratio NaOH:HCl is 1:1

Therefore 0.00250 mol of NaOH reacts with 0.00250 mol of HCl

Step 3: Calculate the concentration of hydrochloric acid in mol/dm3

Volume of hydrochloric acid = 20.00 ÷ 1000 = 0.0200 dm3

Concentration in mol/dm3 =

= 0.125 mol/dm3

Step 4: Calculate the concentration of hydrochloric acid in g/dm3

Relative formula mass of HCl = 1 + 35.5 = 36.5

Mass = relative formula mass × amount

Mass of HCl = 36.5 × 0.125

= 4.56 g

So concentration = 4.56 g/dm3

8 0

3 years ago

Which of the following processes will determine the number of moles in a sample? Dividing the mass of the sample by Avogadro's n

Olenka [21]

The answer is: Dividing the number of molecules in the sample by Avogadro's number.

The Avogadro’s number is the number of atoms in 12 grams of the isotope carbon-12 (¹²C).

Na is Avogadro number or Avogadro constant (the number of particles, in this example carbon, that are contained in the amount of substance given by one mole).

The Avogadro number has value 6.022·10²³ 1/mol in the International System of Units; Na = 6.022·10²³ 1/mol.

For example:

N(Ba) = 2.62·10²³; number of atoms of barium.

n(Ba) = N(Ba) ÷ Na.

n(Ba) = 1.3·10²⁴ ÷ 6.022·10²³ 1/mol.

n(Ba) = 2.158 mol; amount of substance of barium.

6 0

3 years ago

Root nodules are associations between bacteria and plant roots responsible for

max2010maxim [7]

Answer: Root nodules are associations between bacteria and plant roots responsible for nitrogen fixation.

Explanation:

As nitrogen present in atmosphere cannot be used by plants directly.
Nitrogen present in atmosphere is converted into nitrogen compounds by bacteria which is present in root nodules of a plant.
These compounds of nitrogen are then used by plants for various functions.

8 0

3 years ago

Equal amounts of four gases are placed in identical containers at the temperatures that are noted below. Samples of Gases at Dif

Alborosie

Answer : S) 33.2 °C

Explanation : When the equal amounts of gases are placed in identical containers but subjected to different temperatures would exert pressure in different amount which will in turn increase the rate of collision between the molecules of gas.

So, when the temperature is increased to maximum greater amount of force would be exerted and the gas molecules will collide with a larger force. Hence the answer will be as the highest temperature i.e. 33.2 °C

4 0

3 years ago