Answer: 2.8275grams
Explanation: A buffer is made btw a weak acid and it salt. In a solution made by dissolving a weak acid in solution, equilibrium is set up btw ionised and unionised ion. For Benzoic acid
C6H5COOH....> C6H5COO- + H+
Ka = [C6H5COO-] [H+]/ [C6H5COOH].......(1)
using Ka = 6.5× 10^-5, [C6H5COOH] = 0.02M. PH= - log[H+] ....> [H+]= 10^-4M.
Putting the values in(1)
[C6H5COO-]= 6.5× 10^-5 × 0.02/ 10^-4
[C6H5COO-] = 0.013M = Molarity of sodium benzoate
Mole(C6H5COONa) = 0.013 × Volume = 0.013mol/litre × 1.5 litre
Mole(C6H5COONa) = 0.0195mol
Mass(C6H5COONa) = 0.0195 × Molar mass
Mass(C6H5COONa) = 2.8275g
Can you give more information?
Answer:
1.586x10^-9
Explanation:
To make a multiplication in scientific notation we need to multiply the coefficients and sum the exponents:
Coefficients: 2.600 * 6.1000 = 15.86
Exponents: -5 + (-5) = -10
The result is:
15.86x10^-10
As the scientific notation must be given with only 1 number in the left of the point:
<h3>1.586x10^-9</h3>
Density is the measure of a material's mass per unit volume, used in many aspects of science, engineering and industry. Density can be calculated by dividing an object's mass by its volume. Since different materials have different densities, measuring an object's density can help determine which materials are in it. Finding the density of a metal sample can help to determine its purity.When measuring liquids and regularly shaped solids, mass and volume can be discovered by direct measurement and these two measurements can then be used to determine density. Using a pan balance, determine and record the mass of an object in grams. Using a vernier caliper or ruler, measure the length, depth and width of the object in centimeters. Multiply these three measurements to find the volume in cubic centimeters. Divide the object's mass by its volume to determine its density. Density is expressed in grams per cubic centimeter or grams per milliliter.
(this can be split into two paragraphs)
