A as if the cell is placed in a solution with the same solute and water potential as it no water moves in nor out so the cells remains in homoeostasis
hope that helps
Answer:
Cabon-12 has same average atomic weight and mass number.
Explanation:
carbon-12 has average atomic weight 12 amu and mass number of 12.
amu represents average of mass of a nucleon.
As carbon-12 has same average atomic mass and mass number therefore carbon-12 is a good standard to determine average mass of a nucleon.
Again, abundance of carbon-12 isotope is almost equal to 99%. Therefore fluctuation of average atomic weight from 12 amu is very very low.
So, carbon-12 is taken as a standard to determine mass of a nucleon.
Hence atomic mass of carbon-12 is 12 amu.
Question options:
A) K2SO4
B) FeCl₃
C) NaOH
D) NH₃
E) KCl
Answer:
D. NH₃
Explanation:
K2SO4 = 2 K+ + SO42-
[K+]= 2 x 1.0 = 2.0 M ; [SO42-] = 1.0 M
total concentrations of ions = 2.0 + 1.0 = <em>3.0 M</em>
FeCl3 = Fe3+ + 3Cl-
[Fe3+] = 1.0 M ; [Cl-] = 3 x 1.0 = 3.0
total concentration ions = 1.0 + 3.0 =<em> 4.0 M</em>
NaOH = Na+ + OH-
[Na+] = [OH-] = 1.0 M
total concentration ions = 1.0 + 1.0 = <em>2.0 M</em>
<u>NH3 is a weak acid so the concentration of NH4+ and OH- </u><u><em>< 2.0</em></u>
KCl = K+ + Cl-
[K+] = [Cl-] = 1.0 M
total concentration ions = 1.0 + 1.0 =<em> 2.0 M</em>
Answer:
b. 2.28 M
Explanation:
The reaction of neutralization of NaOH with H2SO4 is:
2NaOH + H2SO4 → Na2SO4 + 2H2O
<em>Where 2 moles of NaOH react per mole of H2SO4</em>
<em />
To solve the concentration of NaOH we need to find the moles of H2SO4. Using the chemical equation we can find the moles of NaOH that react and with the volume the molar concentration as follows:
<em>Moles H2SO4:</em>
45.7mL = 0.0457L * (0.500mol/L) = 0.02285 moles H2SO4
<em>Moles NaOH:</em>
0.02285 moles H2SO4 * (2moles NaOH / 1 mol H2SO4) = 0.0457moles NaOH
<em>Molarity NaOH:</em>
0.0457moles NaOH / 0.020L =
2.28M
Right option:
<h3>b. 2.28 M</h3>
Answer:
B) 2
Explanation:
Significant figures : The figures in a number which express the value -the magnitude of a quantity to a specific degree of accuracy is known as significant digits.
The rule apply for the multiplication and division is :
The least number of significant figures in any number of the problem determines the number of significant figures in the answer.
The rule apply for the addition and subtraction is :
The least precise number present after the decimal point determines the number of significant figures in the answer.
(3.478-2.31) = 1.168 ≅ 1.17 (Rounded to least decimal digit)
(4.428-3.56) = 0.868 ≅ 0.87 (Rounded to least decimal digit)
So,
1.17 * 0.87 = 1.0 (Rounded to least significant)
Answer - two significant digits