Answer:
5.37 × 10⁻⁴ mol/L
Explanation:
<em>A chemist makes 660. mL of magnesium fluoride working solution by adding distilled water to 230. mL of a 0.00154 mol/L stock solution of magnesium fluoride in water. Calculate the concentration of the chemist's working solution. Round your answer to 3 significant digits.</em>
Step 1: Given data
- Initial concentration (C₁): 0.00154 mol/L
- Initial volume (V₁): 230. mL
- Final concentration (C₂): ?
- Final volume (V₂): 660. mL
Step 2: Calculate the concentration of the final solution
We want to prepare a dilute solution from a concentrated one. We can calculate the concentration of the final solution using the dilution rule.
C₁ × V₁ = C₂ × V₂
C₂ = C₁ × V₁ / V₂
C₂ = 0.00154 mol/L × 230. mL / 660. mL = 5.37 × 10⁻⁴ mol/L
Molar mass :
Cl₂ = 71.0 g/mol Na = 23.0 g/mol
<span>2 Na + Cl</span>₂<span> = 2 NaCl
</span>
2 x 23 g Na -------> 71.0 g Cl₂
96.6 g Na ----------> ?
Mass Cl₂ = ( 96.6 x 71.0 ) / ( 2 x 23 )
Mass Cl₂ = 6858.6 / 46
= 149.1 g of Cl₂
hope this helps!
Answer : The correct option is, (b) +115 J/mol.K
Explanation :
Formula used :
where,
= change in entropy
= change in enthalpy of vaporization = 40.5 kJ/mol
= boiling point temperature = 352 K
Now put all the given values in the above formula, we get:
Therefore, the standard entropy of vaporization of ethanol at its boiling point is +115 J/mol.K
Answer:
Iron has 26 electrons. Potassium has 39 neutrons. Nickel has 28 protons.
Explanation:
