Abbreviation for mole

Suppose you are working with a NaOH stock solution but you need a solution with a lower concentration for your experiment. Calcu

Monica [59]

Answer: The volume of the 1.224 M NaOH solution needed is 26.16 mL

Explanation:

In order to prepare the dilute NaOH solution, solvent is added to a given amount of the NaOH stock solution up to a final volume of 250.0 mL.

Since only solvent is added, the amount of the solute, NaOH, in the dilute solution is the same as in the volume taken from the stock solution.

Molarity (M) is calculated from the following equation:

M = n ÷ V

where n is the number of moles of the solute in the solution, and V is the volume of the solution.

Accordingly, the number of moles of the solute is given by

n = M x V

Now, let's designate the stock NaOH solution and the dilute solution as (1) and (2), respectively . The number of moles of NaOH in each of these solutions is:

n (1) = M (1) x V (1)

n (2) = M (2) x V (2)

As the amount of NaOH in the dilute solution is the same as in the volume taken from the stock solution,

n (1) = n (2)

and

M (1) x V (1) = M (2) x V (2)

For the stock solution, M (1) = 1.244 M, and V (1) is the volume needed. For the dilute solution, M (2) = 0,1281 M, and V (2) = 250.0 mL.

The volume of the stock solution needed, V (1), is calculated as follows:

V (1) = M (2) x V (2) ÷ M (1)

V (1) = 0.1281 M x 250.0 mL ÷ 1.224 M

V (1) = 26.16 mL

The volume of the 1.224 M NaOH solution needed is 26.16 mL.

7 0

3 years ago

Can someone help me with these questions?

Gennadij [26K]

Answer:

9) Substitution Reaction

10) Covalent Bond

11) Ionic Bond

12) Covalent Bond

13) Ionic Bond

14) 9 atoms

Explanation:

9) Substitution Reaction: Substitution reaction is a chemical reaction in which one atom, ion or species replaced by another atom, ion or species

10) Covalent Bond: Covalent bond is a bond that formed between two nonmetals, when both the species are non metal, the electronegativity of both the nonmetals are comparatively same, hence any of both do not pulls completely electron of other & the bond is formed by the sharing of electron.

11) Ionic Bond: We know that nonmetals have high electronegativity than those of metals, due to high electronegativity non metals pulls the electrons of metals but there is enough interaction that non metal do not escape after pulling the electron, & an ionic bond generates where non metals possess negative charge & positive charge goes to metal.

12) Covalent Bond: The bond formed between two atoms having less electronegativity diffrence by sharing of electron pair is know as covalent bond. for e.g the Carbon - Hydrogen bond in methane (CH4) molecule is covalent bonded because the electronegativity of carbon is 2.5 & that of hydrogen is 2.1 which is almost close, hence the bond formed is covalent.

13) Ionic Bond: The bond formed between two atoms having high electronegativity diffrence & the bond formed is due to complete transfer of electron by one species. For e.g. NaCl the sodium is a metal having electronegativity 0.9 and chlorine is non metal having electronegativity 3.0 the electronegativity diffrence is too high, hence the chlorine behaves as Cl- ion that of sodium as Na+, both the components behaves as ion but they are bonded &that bond is called as Ionic bond.

14) 9 Atoms: One molecule of water (H2O) posses three atoms, two hydrogen atoms & one oxygen atom, the number of atoms in 3 molecules of water 3×3 = 9 atoms.

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3 0

2 years ago

The number of neutrons and protons in the nuclei of two atom A and B is as follow: [A] proton= 8 and neutron = 8, [B] proton = 8

sveticcg [70]

A.atomic mass(a)=16
atomic mass(b)=18
b.a and b are isotopes
c.(a)=2,6
(b)=2,6

4 0

3 years ago

Rank the following solutions in order of increasing acidity (least acidic to most acidic): I: [H3O+] = 1x10−5 II: [OH−] = 1x10−1

kozerog [31]

Answer: option C) II < III < I

i.e [OH−] < [H3O+] < I

Explanation:

First, obtain the pH value of I and II, then compare both with III.

For I

Recall that pH = -log (H+)

So pH3O = -log (H3O+)

= - log (1x10−5)

= 4

For II

pOH = - log(OH-)

= - log(1x10−10)

= 9

For III

pH = 6

Since, pH range from 1 to 14, with values below 7 to be acidic, 7 to be neutral, above 7 to be alkaline: then, 9 < 6 < 4

Thus, the following solutions from least acidic to most acidic is II < III < I

6 0

3 years ago

Elements that are arranged in the same column on the periodic table belong to the same family of elements. the atoms of elements

Vlad [161]

The answer is: c. electrons

4 0

4 years ago