Which sample is a pure substance?

Correct Answer: 18 gms

Explanation:

The molar mass of H2O can be calculated as the following.

M(H2O)= [2 x M(H)] + [M(O)].

And we know that M(H) = 1g/mol, M(O) = 16g/mol.

So, M(H2O)= 2x1 + 16 = 18g/mol,

That means 1 mole of H2O contains 18g.

 

Hence, one mole of H2O corresponds to 18 grams.

Correct Answer: Fructose

Explanation:

Fructose is an Organic molecule among the given options.

  

Organic Molecules :

An organic molecule is one which contains carbon, although not all compounds that contain carbon are organic molecules. Noticeable exceptions are carbon monoxide (CO), carbon dioxide (CO2), carbonates (e.g. calcium carbonate), carbides (e.g. calcium carbide) and cyanides (e.g. sodium cyanide). Pure carbon compounds such as diamond and graphite are also not organic compounds. Organic molecules can range in size from simple molecules to complex structures containing thousands of atoms.

 

Although carbon is present in all organic compounds, other elements such as hydrogen (H), oxygen(O), nitrogen (N), sulfur (S) and phosphorus (P) are also common in these molecules.

 

In simple, Molecules needed for life that have carbon are called Organic Molecules.

Correct Answer: ammonia

Explanation:

Ammonia is a base. One adding ammonia to water,the resulting solution will become basic. pH of an alkaline solution is 7. So the pH will increase

Correct Answer: Zymase

Correct Answer: Tritium

Correct Answer: All the above

Explanation:

Chemical weathering is what happens when rocks are broken down and chemically altered.

Chemical weathering is the breakdown of rocks by chemical reactions. Chemical weathering involves changes in the chemical composition of the existing rock to form new rock. Some examples of chemical weathering are hydrolysis, oxidation, carbonation, dissolution, etc.

Correct Answer: K

Explanation:

For neutral atoms, the periodic trends in atomic size can be described like this

Atomic size decreases when going from left to right across a period,
Atomic size increases when going from top to bottom down a group.

 

Let's use these trends to try and figure out which atom would have the largest radius.

If you look at elements that are located in the same group, potassium will have a larger atomic radius when compared with sodium. Likewise, bromine will have a larger atomic radius when compared with chlorine.

Now focus on potassium and bromine. Since potassium is located at the start of period 3, and bromine at the end of the same period, potassium will have a larger atomic radius than bromine, and thus the largest atomic radius of the four given atoms.

Correct Answer: A vinyl group

Explanation:

C = } C H 2 ? O z o n o l y s i s H C H O

Vinylic group.

Correct Answer: 63 g/mol

Explanation:

Calculation of molar mass of HNO3:

Atomic masses of H, N, O are 1, 14, 16 respectively

Now the molar mass of HNO3 is

HNO3 = 1X1 + 1X14 + 3X16

= 1 + 14 + 48

= 63 g/mol or amu.

Correct Answer: It is insoluble in ether and other Non-polar solvents

Explanation:

Sodium hydroxide, also known as lye and caustic soda, is an inorganic compound with the formula NaOH. It is a white solid ionic compound consisting of sodium cations Na+ and hydroxide anions OH?.

Properties:

1. It is highly soluble in water, and readily absorbs moisture and carbon dioxide from the air.

2. NaOH is insoluble in ether and other non-polar solvents.

3. It is an odorless compound.

 

Uses:

Sodium hydroxide is used in many industries: in the manufacture of pulp and paper, textiles, drinking water, soaps and detergents, and as a drain cleaner.