Q: A scientist is studying a molecule with the formula C$$_6H$_{12}O$_6. $$What is the molecular weight (MW) of this molecule? (Atomic masses: C = 12, H = 1, O = 16)

$$6 \times 12 + 12 \times 1 + 6 \times 16 = 180$$

Q: If a solution has a hydrogen ion concentration of $$[H^+] = 1 \times 10$$^{-4}$$ M, what is its pH?

$$pH = -\log(1 \times 10$$^{-4}$$) = 4$$

Question 1

Which property of water is primarily responsible for the phenomenon of surface tension, allowing insects to walk on water?

Accepted Answer

Cohesion

Question 2

A scientist is studying a molecule with the formula C$$_6H$_{12}O$_6. $$What is the molecular weight (MW) of this molecule? (Atomic masses: C = 12, H = 1, O = 16)

Accepted Answer

$$6 	imes 12 + 12 	imes 1 + 6 	imes 16 = 180$$

Question 3

Which functional group is responsible for making amino acids basic and able to accept protons?

Accepted Answer

Amino (-NH$$_2)$$

Question 4

If a solution has a hydrogen ion concentration of $$[H^+] = 1 	imes 10$$^{-4}$$ M, what is its pH?

Accepted Answer

$$pH = -\log(1 	imes 10$$^{-4}$$) = 4$$

Question 5

Which statement best explains why ice floats on liquid water?

Accepted Answer

Ice is less dense than liquid water due to hydrogen bonding creating an open lattice structure.

Question 6

A molecule with a full valence shell is most likely to be:

Accepted Answer

Stable and inert

Question 7

Which type of chemical bond involves the complete transfer of electrons from one atom to another?

Accepted Answer

Ionic bond

Question 8

During cellular respiration, glucose is oxidized to CO$$_2$$ and oxygen is reduced to H$$_2O. $$Which mnemonic helps remember this process?

Accepted Answer

LEO says GER: Lose Electrons Oxidation, Gain Electrons Reduction

Question 9

Which property of water allows it to dissolve ionic compounds like NaCl?

Accepted Answer

Polarity

Question 10

A solution is prepared by dissolving 0.5 moles of NaCl in 1 liter of water. What is the molarity (M) of the solution?

Accepted Answer

$$M = \frac{0.5}{1} = 0.5$$\ M

Question 11

Which functional group is found in sugars and is polar, allowing it to form hydrogen bonds?

Accepted Answer

Hydroxyl (-OH)

Question 12

Which of the following best describes a cation?

Accepted Answer

An atom that has lost electrons and has a positive charge

Question 13

Which functional group is responsible for stabilizing protein structure by forming cross-links?

Accepted Answer

Sulfhydryl (-SH)

Question 14

Which of the following is true about the atomic number of an element?

Accepted Answer

It is the number of protons in the nucleus.

Question 15

A molecule of water (H$$_2O) $$has partial charges on its atoms. What type of bond is formed between two water molecules?

Accepted Answer

Hydrogen bond

Question 16

Which property of water helps moderate Earth's climate by absorbing large amounts of heat with only a slight change in temperature?

Accepted Answer

High specific heat

Question 17

Which of the following statements about carbon is correct?

Accepted Answer

Carbon has four valence electrons, allowing it to form long chains and complex structures.

Question 18

Which of the following best describes a polar covalent bond?

Accepted Answer

Electrons are shared unequally, resulting in partial charges.

Question 19

A solution has a pH of 9. Which of the following statements is true?

Accepted Answer

The solution is basic and has a low concentration of H$$^+$$ ions.

Question 20

Which functional group contributes a negative charge and is important for energy storage in ATP?

Accepted Answer

Phosphate (-PO$$_4$$^{2-}$$)

Chapter 2: Water and Carbon – The Chemical Basis of Life (Study Notes)

Guida di studio - Domande di pratica

Study guide - Flashcard