Answer:
[Au] = 0.171 M
Explanation:
For this question, we assume the rock is 100 % gold.
First of all, we determine the moles of gold
67.3 g . 1mol/ 196.97g = 0.342 moles
Molar concentration is defined as the moles of solute, contained in 1L of solution.
Our solution volume is 2L.
M = 0.342 mol / 2L = 0.171
Molar concentration, also called molarity of solution is the most typical unit of concentration.
Heptane means seven carbon atoms and since the general formula is CnH2n+2, heptane will be C7H16
Answer:Most elements on the periodic table are metals. Looking at the periodic table shows that most elements are metallic.
Explanation: Sorry if this want what you were looking for
Answer:
The concentration the student should write down in her lab is 2.2 mol/L
Explanation:
Atomic mass of the elements are:
Na: 22.989 u
S: 32.065 u
O: 15.999 u
Molar mass of sodium thiosulfate, Na2S2O3 = (2*22.989 + 2*32.065 + 3*15.999) g/mol = 158.105 g/mol.
Mass of Na2S2O3 taken = (19.440 - 2.2) g = 17.240 g.
For mole(s) of Na2S2O3 = (mass taken)/(molar mass)
= (17.240 g)/(158.105 g/mol) = 0.1090 mole.
Volume of the solution = 50.29 mL = (50.29 mL)*(1 L)/(1000 mL)
= 0.05029 L.
To find the molar concentration of the sodium thiosulfate solution prepared we use the formula:
= (moles of sodium thiosulfate)/(volume of solution in L)
= (0.1090 mole)/(0.05029 L)
= 2.1674 mol/L