Answer : The mass of solute in solution is
.
Solution : Given,
Molarity = 0.730 M
Volume of solution = 1.421 L
Molar mass of sodium carbonate = 105.98 g/mole
Formula used for Molarity :

where,
w = mass of solute
M = Molar mass of solute
V = volume of solution in liter
Sodium carbonate is solute and water is solvent.
Now put the given values in above formula, we get the mass of solute in solution.

By rearranging the terms, we get

Therefore, the mass of solute in solution is
.
Answer:
The correct answer is: d. The pKa of the chosen buffer should be close to the optimal pH for the biochemical reaction.
Explanation:
The buffer resist or maintain the change in pH in case of Acid or basic addition to the solution. The buffer capacity should be within one or two pH units when compared to the optimal pH.
Thus it is important to select a buffer with pKa close to the optimum pH of the reaction because the ability for the buffer to maintain the pH is is great at the pH close to pKa.
Specific gravity is the ratio of density of substance and density of water
We know that density of water = 1 g /mL at standard conditions
now as given that the 0.8 Kg of the substance / object is able to displace 500mL of water , it means that
Mass of object = 800g
The volume occupied by 800g of object = 500 mL
Density = mass / volume
Density of object = 800 / 500= 1.6 g / mL
The specific gravity of object = density of object / density of water = 1.6 / 1 = 1.6 (no units)
Answer:
20.0928.
Explanation:
The average atomic mass is (90 * 19.992 + 10* 21) / 100
= 20.0928.
Answer:
mining of clay limestone and then heated to a certain temperature of 1450⁰ in a cement kiln