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- Question
Which of the following atoms has the largest radius?
Options- A. Br
- B. K
- C. Na
- D. Cl
- Correct Answer
- K
ExplanationFor 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.
- 1. Which of the following is an example of chemical weathering?
Options- A. Oxidation
- B. Acid rains
- C. Carbonation
- D. All the above Discuss
- 2. Which sample is a pure substance?
Options- A. Table salt
- B. Pure water
- C. a test tube of zinc oxide
- D. All the above Discuss
- 3. What does one mole of H2O correspond to
Options- A. 16 gms
- B. 18 gms
- C. 20 gms
- D. 22 gms Discuss
- 4. Which of the following is an Organic Molecule?
Options- A. Nitrogen gas
- B. Ammonia
- C. Fructose
- D. Water Discuss
- 5. The pH of pure water is nearly 7.It will increase on the addition of
Options- A. ammonia
- B. cane sugar
- C. common salt
- D. hydrochloric acid Discuss
- 6. Ozonolysis of an organic compound gives formaldehyde as one of the products. This confirms the presence of :
Options- A. An acetylenic triple bond
- B. Two ethylenic double bonds
- C. A vinyl group
- D. An isopropyl group Discuss
- 7. Molar mass of HNO3?
Options- A. 63 g/mol
- B. 53 g/mol
- C. 48 g/mol
- D. 52 g/mol Discuss
- 8. Which of the following is a property of sodium hydroxide?
Options- A. It is insoluble in ether and other Non-polar solvents
- B. It is slowly soluble in water
- C. It has an odor of rotten egg smell
- D. All the above Discuss
- 9. Which is a characteristic of a Mixture?
Options- A. a pure substance
- B. chemically comined
- C. they can be mixed in some fixed ratio
- D. it is either homogenous or heterogenous Discuss
- 10. When Ionic bonds are formed metallic atoms tend to
Options- A. share electrons
- B. gain electrons
- C. lose electrons
- D. None of above Discuss
Chemistry problems
Search Results
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: 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: A vinyl group
Explanation:
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.
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
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