A. Distinguish between the mass of a molecule and the mass of a mole, using NaCl in your example. B. Calculate the mass of a mole of NaCl in g, using the mass of one Da (amu). C. Calculate the mass of a dozen NaCl molecules, a dozen donuts, and a mole of donuts, assuming a 30 gram donut.
What will be an ideal response?
A. The mass of a molecule is determined by the mass of its component atoms. From the periodic table, the mass of
Na is 23 amu and of Cl is nearly 36 amu, so the mass of one molecule of NaCl is 59 Da. A mole is like a dozen, i.e., it
is a particular number of items, specifically 6.02 × 10 23.
B. A mole of NaCl = 59 Da × 6.02 × 10 23 = 3.55 × 10 25 Da.
1 Da = 1.66 × 10 -27 kg, so 3.55 × 10 25 Da × 1.66 × 10 -27 kg/Da × 1000 g/kg = 59 g.
C. A dozen NaCl molecules: 12 × 59 Da × 1.66 × 10 -27 kg/Da × 1000 g/kg = 1.2 × 10 -21 g.
A dozen donuts: 12 × 30 g = 360 g. A mole of donuts: 6.02 × 10 23 × 30 g = 1.8 × 10 25 g.
You might also like to view...
Cardiac tamponade refers to:
A) the effect of a pneumothorax on the heart. B) the buildup of fluid in the pericardial cavity that impedes the pumping of the heart. C) the rustle-of-silk sound heard in a stethoscope when there is pericarditis. D) pericardial calcification. E) pain from a heart attack.
Match the type of cell junction with the best description. Answers may be used once, more than once, or not at all
1. simplest cell-cell junction 2. contributes to the blood-brain barrier 3. can be cell-matrix junctions 4. their loss is characteristic of cancer A. gap junction B. tight junction C. anchoring junction
Receptors that combine phasic and tonic coding
A) function in sensations like crude touch. B) convey extremely complicated sensory information to the CNS. C) perceive sensory information. D) are most likely to be peripheral sense receptors. E) do not send sensory information to the CNS.
________, thereby stimulating the release of a paracrine factor from the macula densa that would ________.
A) afferent arteriolar pressure : constrict the afferent arteriole B) flow of tubular fluid : constrict the afferent arteriole C) flow of tubular fluid : dilate the afferent arteriole D) afferent arteriolar pressure : increase filtrate flow E) flow of tubular fluid : constrict the efferent arteriole