Chemistry, 2021, JAMB Exam, Exam, Paper 1 | Objectives

Paper Info

Year :

2021

Title :

Chemistry

Exam :

JAMB Exam

Paper 1 | Objectives

11 - 20 of 40 Questions

#	Question	Ans
11.	The gas which causes global warming is? A. O\(_{2}\) B. CO\(_{2}\) C. N\(_{2}\) D. He Show Content Detailed Solution Carbon dioxide, a colorless gas having a faint sharp odor and a sour taste. It is a greenhouse gas. Global warming occurs when carbon dioxide (CO2) and other air pollutants collect in the atmosphere and absorb sunlight and solar radiation that have bounced off the earth’s surface. Normally this radiation would escape into space, but these pollutants, which can last for years to centuries in the atmosphere, trap the heat and cause the planet to get hotter. These heat-trapping pollutants—specifically carbon dioxide, methane, nitrous oxide, water vapor, and synthetic fluorinated gases—are known as greenhouse gases, and their impact is called GREENHOUSE EFFECT There is an exp	B
12.	Oxygen is absent in? A. Kerosene B. Soil C. Glass D. Cement Show Content Detailed Solution Kerosene contains hydrocarbon with twelve to eighteen carbon atoms per molecule There is an explanation video available below.	A
13.	A sample of any of the following substances disappears after some time when exposed to air like camphor, naphthalene, or dry ice. This phenomenon is called? A. Sublimation B. Evaporation C. Diffusion D. Radiation Show Content Detailed Solution Sublimation is the transition of a substance directly from the solid to the gas state, without passing through the liquid state. Familiar substances that sublime readily include iodine, dry ice, menthol, and camphor. There is an explanation video available below.	A
14.	The maximum electron in N shell is? A. 2 B. 8 C. 18 D. 32 Show Content Detailed Solution The N shell is the fourth orbit with 32 max number of electrons using 2n\(^2\) There is an explanation video available below.	D
15.	Neutrons were discovered by? A. James Chadwick B. Ernest Rutherford C. J.J Thompson D. John Dalton Show Content Detailed Solution - Sir James Chadwick, was a British physicist who was awarded the 1935 Nobel Prize in Physics for his discovery of the neutron in 1932. - Ernest Rutherford postulated the nuclear structure of the atom, discovered alpha and beta rays, and proposed the laws of radioactive decay. - Sir Joseph John Thomson was a British physicist and Nobel Laureate in Physics, credited with the discovery of the electron, the first subatomic particle to be discovered. - John Dalton was an English chemist, physicist and meteorologist. He is best known for introducing the atomic theory into chemistry There is an explanation video available below	A
16.	Which of the following is a form of calcium carbonate?I. limestone II. marble III. chalk Iv. egg-shells A. I only B. I, II and IV C. I and II only D. I, II, III, and IV Show Content Detailed Solution - Calcium trioxocarbonate (IV) occurs abundantly in earth's crust as limestone, chalk and marble - Eggshell is made almost entirely of calcium carbonate (CaCO3) crystals. There is an explanation video available below.	D
17.	Soaps clean surfaces on the principle based on? A. viscosity B. floatation C. elasticity D. surface tension Show Content Detailed Solution Since the surface tension forces become smaller as the distance between water molecules increases, the intervening soap molecules decrease the surface tension. There is an explanation video available below.	D
18.	The reactivity of fluorine is due to? A. its high electro negativity B. small size of fluorine atom C. availability of D-orbitals D. strong f-f bond Show Content Detailed Solution fluorine (F), most reactive chemical element and the lightest member of the halogen elements. As the most electronegative element, it is extremely reactive. There is an explanation video available below.	A
19.	The mass number of a nucleus is? A. Always less than its atomic number B. The sum of the number of protons and neutrons present in the nucleus C. Always more than the atomic weight D. A fraction Show Content Detailed Solution mass number, is the sum of the numbers of protons and neutrons present in the nucleus of an atom. There is an explanation video available below.	B
20.	The mass of one Avogadro number of helium atoms is? A. 1.00gram B. 4.00gram C. 8.00gram D. 6.00gram Show Content Detailed Solution Avogadro's number is an absolute number: there are 6.022×10\(^23\) elementary entities in 1 mole. helium has a molar mass of 4.0 grams per mole. So one mole of helium has a mass of 4.0 grams. There is an explanation video available below.	B

11.	The gas which causes global warming is? A. O\(_{2}\) B. CO\(_{2}\) C. N\(_{2}\) D. He Show Content Detailed Solution Carbon dioxide, a colorless gas having a faint sharp odor and a sour taste. It is a greenhouse gas. Global warming occurs when carbon dioxide (CO2) and other air pollutants collect in the atmosphere and absorb sunlight and solar radiation that have bounced off the earth’s surface. Normally this radiation would escape into space, but these pollutants, which can last for years to centuries in the atmosphere, trap the heat and cause the planet to get hotter. These heat-trapping pollutants—specifically carbon dioxide, methane, nitrous oxide, water vapor, and synthetic fluorinated gases—are known as greenhouse gases, and their impact is called GREENHOUSE EFFECT There is an exp	B
12.	Oxygen is absent in? A. Kerosene B. Soil C. Glass D. Cement Show Content Detailed Solution Kerosene contains hydrocarbon with twelve to eighteen carbon atoms per molecule There is an explanation video available below.	A
13.	A sample of any of the following substances disappears after some time when exposed to air like camphor, naphthalene, or dry ice. This phenomenon is called? A. Sublimation B. Evaporation C. Diffusion D. Radiation Show Content Detailed Solution Sublimation is the transition of a substance directly from the solid to the gas state, without passing through the liquid state. Familiar substances that sublime readily include iodine, dry ice, menthol, and camphor. There is an explanation video available below.	A
14.	The maximum electron in N shell is? A. 2 B. 8 C. 18 D. 32 Show Content Detailed Solution The N shell is the fourth orbit with 32 max number of electrons using 2n\(^2\) There is an explanation video available below.	D
15.	Neutrons were discovered by? A. James Chadwick B. Ernest Rutherford C. J.J Thompson D. John Dalton Show Content Detailed Solution - Sir James Chadwick, was a British physicist who was awarded the 1935 Nobel Prize in Physics for his discovery of the neutron in 1932. - Ernest Rutherford postulated the nuclear structure of the atom, discovered alpha and beta rays, and proposed the laws of radioactive decay. - Sir Joseph John Thomson was a British physicist and Nobel Laureate in Physics, credited with the discovery of the electron, the first subatomic particle to be discovered. - John Dalton was an English chemist, physicist and meteorologist. He is best known for introducing the atomic theory into chemistry There is an explanation video available below	A

16.	Which of the following is a form of calcium carbonate?I. limestone II. marble III. chalk Iv. egg-shells A. I only B. I, II and IV C. I and II only D. I, II, III, and IV Show Content Detailed Solution - Calcium trioxocarbonate (IV) occurs abundantly in earth's crust as limestone, chalk and marble - Eggshell is made almost entirely of calcium carbonate (CaCO3) crystals. There is an explanation video available below.	D
17.	Soaps clean surfaces on the principle based on? A. viscosity B. floatation C. elasticity D. surface tension Show Content Detailed Solution Since the surface tension forces become smaller as the distance between water molecules increases, the intervening soap molecules decrease the surface tension. There is an explanation video available below.	D
18.	The reactivity of fluorine is due to? A. its high electro negativity B. small size of fluorine atom C. availability of D-orbitals D. strong f-f bond Show Content Detailed Solution fluorine (F), most reactive chemical element and the lightest member of the halogen elements. As the most electronegative element, it is extremely reactive. There is an explanation video available below.	A
19.	The mass number of a nucleus is? A. Always less than its atomic number B. The sum of the number of protons and neutrons present in the nucleus C. Always more than the atomic weight D. A fraction Show Content Detailed Solution mass number, is the sum of the numbers of protons and neutrons present in the nucleus of an atom. There is an explanation video available below.	B
20.	The mass of one Avogadro number of helium atoms is? A. 1.00gram B. 4.00gram C. 8.00gram D. 6.00gram Show Content Detailed Solution Avogadro's number is an absolute number: there are 6.022×10\(^23\) elementary entities in 1 mole. helium has a molar mass of 4.0 grams per mole. So one mole of helium has a mass of 4.0 grams. There is an explanation video available below.	B