An aqueous solution of sodium
hydroxide containing 2g in 200cm^3 of
solution has a concentration of (NaOH =
40).answer in mol\dm^3

2.5×10^-7mol/dm^3

Explanation:

Firstly convert the cm^3 to dm^3

200×1000=200000dm^3

Calculate the g/dm^3

2/200000=0.00001g/dm^3

To calculate mol/dm^3

Mol/dm^3=mass given\molar mass

=0.00001/40

=2.5×10^-7mol/dm^3

0.25mol/dm^3

Explanation:

Let us calculate the number of mole in 2g of NaOH. This is illustrated below:

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

Mass of NaOH given = 2g

Number of mole = Mass /Molar Mass

Number of mole of NaOH = 2/40 = 0.05mole

Volume = 200cm^3

1000cm^3 = 1dm^3

200cm^3 = 200/1000 = 0.2dm^3

Molarity = mole/Volume

Molarity = 0.05/0.2

Molarity = 0.25mol/dm^3

explanation:

let the different atoms be x and y. each with four protons and same mass will be represented as follows.

mass number is number of protons + number of neutrons.

            and  

since, it is given that one has a negative charge while the other is neutral. therefore, there will be increase in number of protons and the atom will be represented as follows.

according to periodic table, mass number of beryllium is 9 and it has atomic number 4 so, the atoms will be and .  

the protons and neutrons will be located inside the nucleus whereas the electrons will be revolving around the nucleus.  

chemical digestion occurs in the stomach were hcl and pepsin forms chyme, the mouth in which salivary amylase breaks down starch to form bolus, and the small intestine specifically the duodenum.