Q: How many particles are in $$2.5$$ moles of RbCl? (Avogadro's number $$= 6.022 \times 10$$^{23}$$)

$$1.55 \times 10$$^{24}$$ particles

Q: A sample contains $$0.246 g of $$CuCl$$_3. $$How many Cu atoms are present? (Molar mass CuCl$$_3$$ = $$169.905 g/$$mol, Avogadro's number $$= 6.022 \times 10$$^{23}$$)

$$8.72 \times 10$$^{20}$$ atoms

Q: How many molecules are in $$10.0 g of H$_2O$$? (Molar mass H$$_2O$$ = $$18.015 g/$$mol, Avogadro's number $$= 6.022 \times 10$$^{23}$$)

$$3.34 \times 10$$^{23}$$ molecules

Question 1

Which of the following best describes valence electrons?

Accepted Answer

Electrons responsible for bonding and found in the outermost shell

Question 2

What is the molecular geometry and polarity of NH$$_3$$?

Accepted Answer

Trigonal pyramidal, polar

Question 3

Which intermolecular force is present in all compounds?

Accepted Answer

London dispersion forces

Question 4

How many valence electrons are present in PCl$$_3$$?

Accepted Answer

$$26$$ valence electrons

Question 5

Which molecule exhibits hydrogen bonding?

Accepted Answer

NH$$_3$$

Question 6

What is the molar mass of Cr(NO$$_3$$)$$_3$$? (Cr: $$51.996 g/$$mol, N: $$14.007 g/$$mol, O: $$15.999 g/$$mol)

Accepted Answer

$$238.018 g/$$mol

Question 7

Convert $$45^	ext{o}C to $$Kelvin.

Accepted Answer

$$318 K$$

Question 8

How many particles are in $$2.5$$ moles of RbCl? (Avogadro's number $$= 6.022 	imes 10$$^{23}$$)

Accepted Answer

$$1.55 	imes 10$$^{24}$$ particles

Question 9

Which statement best describes the difference between electron geometry (EG) and molecular geometry (MG)?

Accepted Answer

EG considers both lone pairs and atoms bonded to the central atom, while MG differentiates between lone pairs and bonded atoms

Question 10

A sample contains $$0.246 g of $$CuCl$$_3. $$How many Cu atoms are present? (Molar mass CuCl$$_3$$ = $$169.905 g/$$mol, Avogadro's number $$= 6.022 	imes 10$$^{23}$$)

Accepted Answer

$$8.72 	imes 10$$^{20}$$ atoms

Question 11

Which of the following molecules is non-polar due to equal sharing of electrons?

Accepted Answer

BF$$_3$$

Question 12

How many molecules are in $$10.0 g of H$_2O$$? (Molar mass H$$_2O$$ = $$18.015 g/$$mol, Avogadro's number $$= 6.022 	imes 10$$^{23}$$)

Accepted Answer

$$3.34 	imes 10$$^{23}$$ molecules

Question 13

Which intermolecular force is the strongest among the following?

Accepted Answer

Hydrogen bonding

Question 14

How many grams of CO$$_2$$ are present in $$3.61 	imes 10$$^{23}$$ molecules? (Molar mass CO_2$ = 44.009$ g/mol, Avogadro's number = 6.022$$ 	imes $$10^{23})$$

Accepted Answer

$$22.0 g$$

Question 15

How many sodium ions are in $$25.0 g of $$NaCl? (Molar mass NaCl = $$58.443 g/$$mol, Avogadro's number $$= 6.022 	imes 10$$^{23}$$)

Accepted Answer

$$2.58 	imes 10$$^{23}$$ ions

Question 16

What is the electron geometry and molecular geometry of CCl$$_4$$?

Accepted Answer

Tetrahedral, tetrahedral

Question 17

Which molecule has a bent molecular geometry and is polar?

Accepted Answer

H$$_2S$$

Question 18

How many grams are in $$5.00 	imes 10$$^{24}$$ molecules of C_2$H_6$? (Molar mass C_2$H_6$ = 30.07$ g/mol, Avogadro's number = 6.022$$ 	imes $$10^{23})$$

Accepted Answer

$$250 g$$

Question 19

Which of the following best describes dipole-dipole forces?

Accepted Answer

Forces between molecules with unequal sharing of electrons

Atoms, Molecules, and Chemical Quantities: Study Notes for GOB Chemistry

Guida di studio - Domande di pratica

Study guide - Flashcard