Which of the following is a property of sodium hydroxide?

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: 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: 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: 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: All the above

Explanation:

A pure substance can be defined as any single type of material that has not been contaminated by another substance. In chemistry, a pure substance has a definite composition. It can be a compound or an element. A pure substance is considered to be a material that consists of one type of "building block" of matter.

Examples of pure substances include tin, sulfur, diamond, water, pure sugar (sucrose), table salt (sodium chloride) and baking soda (sodium bicarbonate).

Tin, sulfur, and diamond are examples of pure substances which are chemical elements. All elements are pure substances.

Water, sugar, salt and baking soda are pure substances which are chemical compounds. Chemical compounds also are pure substances

Correct Answer: it is either homogenous or heterogenous

Explanation:

A mixture is the blending of two or more dissimilar substances.

 

Characteristics of a Mixture:

1. It has No formula.

2. It is an impure sustance

3. They can be mixed in any ratio.

4. The properties of the mixture are the properties of its constituents.

5. Constituents can e easily seperated by physical methods.
eg: Heating, Drying, Crystallization, Distillation etc...

6. It is either homogenous or heterogenous.

 

A major characteristic of mixtures is that the materials do not chemically combine. Mixtures can be divided into those that are evenly distributed (homogeneous) and those that aren't (heterogeneous).

Correct Answer: lose electrons

Explanation:

Ionic bonding is the complete transfer of valence electron(s) between atoms. It is a type of chemical bond that generates two oppositely charged ions. In ionic bonds, the metal loses electrons to become a positively charged cation, whereas the nonmetal accepts those electrons to become a negatively charged anion.

 

Hence, when Ionic bonds are formed metallic atoms tend to lose electrons and become positive ions

Correct Answer: In general, polar solvents dissolve polar solutes, and nonpolar solvents dissolve nonpolar solutes As water molecules are polar, polar molecules dissolves in water

Correct Answer: Nucleic acid

Explanation:

Nucleic acid is a polymer among the given options.

Correct Answer: CF4

Explanation:

You have to consider three things.

1. First, are the bonds polar?

Look at differences in electronegativity and if  it is >0.5, bonds are polar.

 

2. Second, does the molecule have unshared electron pairs?

If so, they generally lead to a polar molecule.

 

3. Third, is the molecule symmetric?

If so, then although the bonds may be polar, the symmetry cancels out the individual bond polarity and the molecule is non polar.

CF4 follows all the rules above and has a symmetric distribution of charge, making it nonpolar. The others all have asymmetric charge distributions.

 

Hence, CF4 represents a Non-polar molecule.