Achemist prepares a solution of silver(i) nitrate (agno3) by measuring out 269. micromol of silver(i) nitrate into a 300. ml volumetric flask and filling the flask to the mark with water. calculate the concentration in mmol/l of the chemist's silver(i) nitrate solution. be sure your answer has the correct number of significant digits.

The concentration of the chemist's silver(I) nitrate  solution is  0.897 mmol/L

Explanation:

Step 1: Data given

Number of moles AgNO3 = 269 micromol = 269 * 10^-6 mol

Volume of AgNO3 = 300 mL = 0.3 L

Molar mass of AgNO3 = 169.87 g/mol

Step 2: Calculate molarity of AgNO3

Molarity = number of moles per volume (in Liters)

Molarity AgNO3 = 269 *10^-6 mol / 0.3 L

Molarity AgNO3 = 8.97 * 10^-4 M

8.97 *10^-4 mol/L = 897 micromol/L = 0.897 mmol/L

The concentration of the chemist's silver(I) nitrate  solution is  0.897 mmol/L

answer : third trial had the contaminated sample and the correct value for dhrxn should be 1000 kj/mol

explanation :

let us write down the given equations

equation 1 :

equation 2 :

equation 3 :

let us use hess's law to find out which 2 equations can be added to get the third equation.

let us reverse equation 2 and multiply it by 2. the new equation that we get is,

equation 4 :

let us add equation 1 & 4

the above equation is similar to equation 3 but has different value for dhrxn.

therefore third trial had the contaminated sample and the correct value for dhrxn should be 1000 kj/mol