A. <em>Concentration in terms of molarity</em>
First, calculate for the molar mass of the given solution, C12H22O11.
m = 12(12) + 22(1) + 11(16) = 232
Calculate for the number of moles.
n = 8.45 g / 232 g/mol = 0.036422 moles
Divide the determined number of moles by volume of solution in L.
V(solution) = (250 mL)(1 L/1000 mL) = 0.25 L
The concentration in molarity is determined by dividing the number of moles by the volume of solution in liters.
M = 0.03622 moles / 0.25 L = 0.146 moles/L
b. <em>Concentration in terms of molality</em>
Calculate the mass of the solvent in kilogram given the volume and its density.
m(solvent) = (1.21 g/cm3)(250 mL)(1 kg/1000 g) = 0.3025 kg
Divide the calculated number of moles by the mass of the solvent in kilograms.
molality = 0.036422 moles/0.3025 kg = 0.12 molal
c. <em>Concentration in terms of weight percent.</em>
The total weight of the solution is equal to 302.5 g.
weight percent of solute = (8.45 g / 302.5 g)(100%) = 2.79%
d. <em>Weight percent in ppm.</em>
weight percent of solute x (10000 ppm/1%)
= (2.79%)(10000 ppm/1%) = 27933.88 ppm
The half life equation is -->P(t) = Pi (0.5) ^ (t/c)
c is equal to the element to reach its half-life (5 seconds)t is equal to the duration of time the element is expose to (20 seconds)Pi is the initial amount (340)0.5 is the base of this exponential function to represent half-life.P(t) is the expression for the function of time
P(20) = 340 (0.5)^20/5P(20) = 340 (0.5) ^4P(20)= 21.25 grams
Fraction = P(t)/Pi = P(20)/Pi =21.25/340 =1/16
Therefore, when given 20 seconds, 340 grams of Fluorine-21 will degrade to 21.25 grams OR 1/16 of its original mass.
Hope this method helps! (This is my answer btw, I think you may have accidentally posted twice?)
Answer:
Explanation:
For water, the temperature needs to be a little over zero degrees Celsius (0C) for you to melt. If you were salt, sugar, or rock, your melting point is higher than that of water.
In ionic bonds electrons are transferred from one species to another and the electrostatic attraction between oppositely charged ions gives rise to the ionic bond.
covalent bonds are when electrons are shared between 2 atoms.
the electronegativity difference between the atoms taking part in the bond will decide if its an ionic bond or covalent bond.
if the electronegativity difference is very large then ionic bond is formed. if the electronegativity difference is very low then covalent bond is formed
the electronegativity difference between H and S is very small therefore they form a covalent bond by sharing their electrons
correct answer is
2) electrons are shared to form a covalent bond
Answer:
B. The time during which a collision between two molecules occurs is negligibly short compared to the time between collisions
Explanation:
Kinetic molecular theory postulates:-
- The gas is composed of small molecules are they are in continuous random motion and having elastic collisions with one another and also with the walls of the container.
- The molecules of the gas does not exert any kind of repulsive or attractive forces on each other and they their size is negligible as compared to the difference between them.
- Pressure exerted by the molecules of the gas results from the collisions which is happening between the molecules of the gas and the walls of the container.
- Average kinetic energy of molecules of the gas is directly proportional to absolute temperature.
Hence, The correct option is:- <u>B. The time during which a collision between two molecules occurs is negligibly short compared to the time between collisions. This is not an important postulate of the kinetic molecular theory.</u>
