MCQOPTIONS
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MCQOPTIONS
This section includes 335 Mcqs, each offering curated multiple-choice questions to sharpen your Chemistry knowledge and support exam preparation. Choose a topic below to get started.
| 251. |
The ion of elements which are good catalyst and have ability to change their oxidation number are |
| A. | Nobel gases |
| B. | transition elements |
| C. | all of them |
| D. | alkalis |
| Answer» C. all of them | |
| 252. |
The electro negativity of hydrogen atom is |
| A. | 2.1 |
| B. | 2.2 |
| C. | 2.3 |
| D. | 2.4 |
| Answer» B. 2.2 | |
| 253. |
Organic molecules with similar relative molecular mass have alcohols bearing high |
| A. | polarity |
| B. | boiling point |
| C. | none |
| D. | volatility |
| Answer» C. none | |
| 254. |
In Calcium chloride, chloride gains |
| A. | two electrons |
| B. | one electron |
| C. | four electrons |
| D. | three electrons |
| Answer» B. one electron | |
| 255. |
One mole of a sodium chloride has number of sodium ions equal to |
| A. | x 1023 |
| B. | x 1023 |
| C. | x 1023 |
| D. | x 1023 |
| Answer» C. x 1023 | |
| 256. |
Reactions are started by attacking on electrically charged end of polar molecule by |
| A. | reagent |
| B. | reactants |
| C. | All of Above |
| D. | catalyst |
| Answer» B. reactants | |
| 257. |
The ionization energies is influenced by the proton number of the atom of |
| A. | molecular charge |
| B. | electron charge |
| C. | nuclear charge |
| D. | proton charge |
| Answer» D. proton charge | |
| 258. |
Salting' is the last stage of manufacture of |
| A. | soap |
| B. | plastic |
| C. | all of them |
| D. | detergent |
| Answer» B. plastic | |
| 259. |
The first ionization energy of potassium is |
| A. | 419 |
| B. | 417 |
| C. | 416 |
| D. | 418 |
| Answer» B. 417 | |
| 260. |
The ionization energies is influenced by atomic radius of |
| A. | atom |
| B. | electron |
| C. | proton |
| D. | ion |
| Answer» B. electron | |
| 261. |
Once formed, how are coordinate covalent bonds different from other covalent bonds? |
| A. | They are more ionic in character. |
| B. | There is no difference. |
| C. | They are stronger. |
| D. | They are weaker. |
| Answer» C. They are stronger. | |
| 262. |
The less the electronegativity differences between two bonded atoms, the greater the _____. |
| A. | ionic character |
| B. | polar character |
| C. | covalent character |
| D. | metallic character |
| Answer» D. metallic character | |
| 263. |
A molecule with a single covalent bond is ____. |
| A. | CO |
| B. | CO2 |
| C. | Cl2 |
| D. | N2 |
| Answer» D. N2 | |
| 264. |
Which of the following elements can form diatomic molecules held together by triple covalent bonds? |
| A. | nitrogen |
| B. | fluorine |
| C. | carbon |
| D. | oxygen |
| Answer» B. fluorine | |
| 265. |
Which of the following diatomic molecules is joined by a double covalent bond? |
| A. | Cl2 |
| B. | N2 |
| C. | O2 |
| D. | He2 |
| Answer» D. He2 | |
| 266. |
Which of the following is the name given to the pairs of valence electrons that do not participate in bonding in diatomic oxygen molecules? |
| A. | unvalenced pair |
| B. | outer pair |
| C. | unshared pair |
| D. | inner pair |
| Answer» D. inner pair | |
| 267. |
Why do atoms share electrons in covalent bonds? |
| A. | to become more polar |
| B. | to attain a noble-gas electron configuration |
| C. | to increase their atomic numbers |
| D. | to become ions and attract each other |
| Answer» C. to increase their atomic numbers | |
| 268. |
Which of the following covalent bonds has the greatest polarity? |
| A. | Na – I |
| B. | S – O |
| C. | C – O |
| D. | Na – Br |
| Answer» E. | |
| 269. |
The number of lone electron pairs in the N2 molecule is ___. |
| A. | 1 |
| B. | 2 |
| C. | 3 |
| D. | 4 |
| Answer» C. 3 | |
| 270. |
In which of the following compounds are hydrogen bonds between molecules the strongest? |
| A. | HF |
| B. | HCl |
| C. | HBr |
| D. | HI |
| Answer» B. HCl | |
| 271. |
What type of chemical bond holds the atoms together within a water molecule? |
| A. | ionic bond |
| B. | nonpolar covalent bond |
| C. | polar covalent bond |
| D. | hydrogen bond |
| Answer» C. polar covalent bond | |
| 272. |
Which of the atoms listed below is the most electronegative? |
| A. | P |
| B. | Cs |
| C. | As |
| D. | Li |
| Answer» B. Cs | |
| 273. |
Classify the O – H bond in CH3OH as ionic, polar covalent, or nonpolar covalent. |
| A. | ionic |
| B. | polar covalent |
| C. | nonpolar covalent |
| D. | None of this |
| Answer» C. nonpolar covalent | |
| 274. |
Which pair of elements would be most likely to form an ionic compound? |
| A. | Cl and I |
| B. | Al and K |
| C. | C and S |
| D. | Cl and Mg |
| Answer» E. | |
| 275. |
The electron dot formula for AsCl3 shows: |
| A. | three single bonds and 10 lone-pairs |
| B. | a total of 84 electron dots |
| C. | one single bond, two double bonds, and 8 lone-pairs |
| D. | two single bonds, one double bond, and 9 lone-pairs |
| Answer» B. a total of 84 electron dots | |
| 276. |
Which one of the following is a polar covalent bond? |
| A. | Si– Si |
| B. | Cl– Cl |
| C. | Ca– Cl |
| D. | P– Cl |
| Answer» E. | |
| 277. |
Which one of the compounds below is most likely to be ionic? |
| A. | NO2 |
| B. | SrBr2 |
| C. | GaAs |
| D. | CBr4 |
| Answer» C. GaAs | |
| 278. |
How many electrons does barium have to give up to achieve a noble-gas electron configuration? |
| A. | 2 |
| B. | 3 |
| C. | 4 |
| D. | 1 |
| Answer» B. 3 | |
| 279. |
What is the formula of the ion formed when potassium achieves noble-gas electron configuration? |
| A. | K+ |
| B. | K2- |
| C. | K2+ |
| D. | K1- |
| Answer» B. K2- | |
| 280. |
What is the name given to the electrons in the highest occupied energy level of an atom? |
| A. | orbital electrons |
| B. | anions |
| C. | valence electrons |
| D. | cations |
| Answer» D. cations | |
| 281. |
How many valence electrons are transferred from the calcium atom to iodine in the formation of the compound calcium iodide? |
| A. | 1 |
| B. | 2 |
| C. | 0 |
| D. | 3 |
| Answer» C. 0 | |
| 282. |
The electron dot formula for O2 shows: |
| A. | a double covalent bond |
| B. | a total of 8 × 2 = 16 electron dots |
| C. | a single covalent bond |
| D. | an ionic bond |
| Answer» B. a total of 8 × 2 = 16 electron dots | |
| 283. |
How does calcium obey the octet rule when reacting to form compounds? |
| A. | It gains electrons. |
| B. | It gives up electrons. |
| C. | It does not change its number of electrons. |
| D. | Calcium does not obey the octet rule. |
| Answer» C. It does not change its number of electrons. | |
| 284. |
What is the charge on the cation in the ionic compound sodium sulfide? |
| A. | 0 |
| B. | 2+ |
| C. | 1+ |
| D. | 3+ |
| Answer» D. 3+ | |
| 285. |
Which of the following ions has a pseudo-noble-gas electron configuration? |
| A. | Fe2+ |
| B. | Cu+ |
| C. | Ni+ |
| D. | Mn2 + |
| Answer» C. Ni+ | |
| 286. |
Which of the following occurs in an ionic bond? |
| A. | Two atoms share two electrons. |
| B. | Two atoms share more than two electrons. |
| C. | Like-charged ions attract. |
| D. | Oppositely charged ions attract. |
| Answer» E. | |
| 287. |
What is the net charge of the ionic compound calcium fluoride? |
| A. | 2- |
| B. | 1- |
| C. | 0 |
| D. | 1+ |
| Answer» D. 1+ | |
| 288. |
Which of the following is NOT a property of a metal? |
| A. | low electronegativity |
| B. | low ionization energy |
| C. | shiny |
| D. | may be solid, liquid, or gas at room temperature |
| Answer» E. | |
| 289. |
Which of the following atoms acquires the most negative charge in a covalent bond with hydrogen? |
| A. | Na |
| B. | S |
| C. | C |
| D. | O |
| Answer» E. | |
| 290. |
Which type of bond would result in a good conductor of electricity when the substance is dissolved in an aqueous solution? |
| A. | ionic |
| B. | nonpolar covalent |
| C. | metallic |
| D. | polar covalent |
| Answer» B. nonpolar covalent | |
| 291. |
What causes hydrogen bonding? |
| A. | motion of electrons |
| B. | sharing of electron pairs |
| C. | bonding of a covalently bonded hydrogen atom with an unshared electron pair |
| D. | attraction between ions |
| Answer» D. attraction between ions | |
| 292. |
When H+forms a bond with H2 O to form the hydronium ion H3O+ , this bond is called a coordinate covalent bond because ____. |
| A. | the electrons are equally shared |
| B. | it forms an especially strong bond |
| C. | both bonding electrons come from the oxygen atom |
| D. | the oxygen no longer has eight valence electrons |
| Answer» D. the oxygen no longer has eight valence electrons | |
| 293. |
Why is hydrogen bonding only possible with hydrogen |
| A. | Hydrogen is the only atom that is the same size as an oxygen atom. |
| B. | Hydrogen's nucleus is electron deficient when it bonds with an electronegative atom. |
| C. | Hydrogen is the most electronegative element. |
| D. | Hydrogen tends to form covalent bonds. |
| Answer» C. Hydrogen is the most electronegative element. | |
| 294. |
Which of the following describes an ionic compound |
| A. | low boiling point |
| B. | easily vaporize |
| C. | low melting point |
| D. | high melting point |
| Answer» E. | |
| 295. |
The melting points of molecular compounds are usually _____. |
| A. | below zero |
| B. | lower than those of ionic compounds |
| C. | equal to those of ionic compounds |
| D. | higher than those of ionic compound |
| Answer» C. equal to those of ionic compounds | |
| 296. |
The relative numbers of atoms of each kind in any chemical compound (using atomic symbols and subscripts) is known as a _____. |
| A. | molecular formula |
| B. | scientific formula |
| C. | compound formula |
| D. | chemical formula |
| Answer» E. | |
| 297. |
Which of the following cannot be represented by a molecular formula? |
| A. | a covalent compound |
| B. | a polar compound |
| C. | a molecular compound |
| D. | an ionic compound |
| Answer» E. | |
| 298. |
How are bond length and bond energies related? |
| A. | they are not related |
| B. | the lower the bond energy, the shorter the bond length |
| C. | the higher the bond energy, the shorter the bond length |
| D. | the higher the bond energy, the longer the bond length |
| Answer» D. the higher the bond energy, the longer the bond length | |
| 299. |
Which type of bonding would be expected between S and Cl? |
| A. | polar covalent |
| B. | ionic |
| C. | non-polar covalent |
| D. | polyionic |
| Answer» B. ionic | |
| 300. |
What type of bonding does NaCl have? |
| A. | polar covalent |
| B. | metallic |
| C. | nonpolar covalent |
| D. | ionic |
| Answer» E. | |