Discussion
Home ‣ General Knowledge ‣ Chemistry Comments
- Question
Which of the following elements is a metalloid?
Options- A. arsenic
- B. boron
- C. antimony
- D. All of the above
- Correct Answer
- All of the above
ExplanationA metalloid is any chemical element which has properties in between those of metals and nonmetals, or that has a mixture of them.
The six commonly recognised metalloids are
boron,
silicon,
germanium,
arsenic,
antimony, and
tellurium.
- 1. Which element is a member of the halogen family?
Options- A. Chlorine
- B. Bromine
- C. Iodine
- D. All of the above Discuss
- 2. Which statement is true of all atoms that are anions?
Options- A. The atom has more electrons than protons
- B. The atom has more protons than electrons
- C. The atom has equal number of protons and electrons
- D. All of the above Discuss
- 3. Which compound contains ionic bonds?
Options- A. CaO
- B. CO2
- C. NO2
- D. NO Discuss
- 4. A disaccharide is formed by the chemical bonding of
Options- A. two monosaccharides
- B. two polysaccharides
- C. one monosaccharide and one polysaccharide
- D. All the above Discuss
- 5. What is the conjugate base of H2O?
Options- A. NH3+
- B. OH-
- C. H2O
- D. All the above Discuss
- 6. Covalent bonds hold atoms together because they
Options- A. fill shells without giving atoms much charge
- B. bring electrons closer to protons
- C. Both A & B
- D. use forces between nuclei as well as forces between electrons Discuss
- 7. Under which conditions are gases most soluble in water?
Options- A. low pressure and low temperature
- B. low pressure and high temperature
- C. high pressure and low temperature
- D. high pressure and high temperature Discuss
- 8. Nucleic acids are polymers of
Options- A. Nucleotides
- B. Aminoacids
- C. Proteins
- D. Sugars Discuss
- 9. What is the oxidation number of carbon in NaHCO3?
Options- A. -4
- B. -3
- C. +4
- D. +2 Discuss
- 10. In a compound, chemical energy is contained in the
Options- A. bonds
- B. movement of the electrons
- C. unbonded electrons
- D. nuclei of the atoms Discuss
Chemistry problems
Search Results
Correct Answer: All of the above
Explanation:
The halogens make up group 17 in the periodic table.
They are five elements:
Chlorine (Cl)
Fluorine (F)
Bromine (B)
Iodine (I)
Astatine (At).
But astatine is not purely halogen as it is radioactive.
Correct Answer: The atom has more electrons than protons
Correct Answer: CaO
Explanation:
An ionic bond is a chemical bond between two atoms in which one atom seems to donate its electron to another atom.
Here in the given compounds, the compound that contains ionic bond is CaO, Calcium oxide.
Correct Answer: two monosaccharides
Explanation:
Disaccharides are formed when two monosaccharides join together by the dehydration synthesis reaction resulting in a glycosidic bond between the two monosaccharide molecules. The reaction produces water as a side product.
Correct Answer: OH-
Explanation:
A conjugate acid, is a species formed by the reception of a proton (H+) by a base?in other words, it is a base with a hydrogen ion added to it.
On the other hand, a conjugate base is what is left over after an acid has donated a proton during a chemical reaction. Hence, a conjugate base is a species formed by the removal of a proton from an acid.
Because some acids are capable of releasing multiple protons, the conjugate base of an acid may itself be acidic.
Represented as the following chemical reaction:
Acid + Base ? Conjugate Base + Conjugate Acid
The water molecule is the conjugate acid of the hydroxide ion after the latter received the hydrogen proton donated by ammonium. On the other hand, ammonia is the conjugate base for the acid ammonium after ammonium has donated a hydrogen ion towards the production of the water molecule. We can also refer to OH- as a conjugate base of H2O, since the water molecule donates a proton towards the production of NH+4 in the reverse reaction, which is the predominating process in nature due to the strength of the base NH3 over the hydroxide ion.
Correct Answer: Both A & B
Explanation:
Covalent bonds hold atoms together because the attraction between the positively charged nuclei and the negatively charged shared electrons is greater than the repulsions between the nuclei themselves.
Correct Answer: high pressure and low temperature
Explanation:
Henry's Law tells that the solubility of a gas is directly proportional to the partial pressure of the gas above the solvent. Hence under high pressure, more gas is dissolved.
Also that Henry's Law involves a constant which is temperature-dependent. Under high temperatures, less gas is dissolved whereas under low temperatures, more gas is dissolved.
For Example ::
You can think of a can of soda. The contents are under pressure and if you shake the can before opening, the soda fizzes out all over as you open it. So the higher the pressure, the more gas or more CO2 can be dissolved in the drink.
Eliminate choices 1 and 2. Now focus on the temperature. Soda goes flat (loses carbonation or gas) as it warms up. Soda is usually served cold because more of the carbonation or CO2 stays in the drink when the soda is cold.
Hence, in high pressure and low temperature conditions gases are most soluble in water.
Correct Answer: Nucleotides
Explanation:
Nucleic acids are polymers of individual nucleotide monomers.
Each nucleotide is composed of three parts:
a 5-carbon sugar,
a phosphate group, and
a nitrogenous base.
Correct Answer: +4
Explanation:
The given compound is NaHCO3 Sodium bicarbonate which is commonly known as Baking soda.
Oxidation numbers are the charges on ions. When a neutral atom loses electrons it becomes positively charged. When a neutral atom gains electrons it becomes negatively charged.
Here the C represents the oxidation state of carbon in this compound. Compounds are electrically neutral, which is why we set the sum of the oxidation states equal to zero.
Sodium has a +1 oxidation state. Hydrogen has a +1 oxidation state. Oxygen has a -2 oxidation state. There are three oxygen atoms, which means the total oxidation state provided by both oxygen ions is -6. Adding up these oxidation states we get:
1 + 1 + (-6) + C = 0
-4 + C = 0
=> C = 4
This means the oxidation state of carbon in this compound is +4.
Correct Answer: bonds
Explanation:
chemical energy is contained in the chemical bonds between the reactants in the chemical compounds.
Comments
There are no comments.More in General Knowledge:
Programming
Copyright ©CuriousTab. All rights reserved.