This problem could be solved easily using the Henderson-Hasselbach equation used for preparing buffer solutions. The equation is written below:
pH = pKa + log[(salt/acid]
Where salt represents the molarity of salt (sodium lactate), while acid is the molarity of acid (lactic acid).
Moles of salt = 1 mol/L * 25 mL * 1 L/1000 mL = 0.025 moles salt
Moles of acid = 1 mol/L* 60 mL * 1 L/1000 mL = 0.06 moles acid
Total Volume = (25 mL + 60 mL)*(1 L/1000 mL) = 0.085 L
Molarity of salt = 0.025 mol/0.085 L = 0.29412 M
Molarity of acid = 0.06 mol/0.085 L = 0.70588 M
Thus,
pH = 3.86 + log(0.29412/0.70588)
pH = 3.48
<h3>Answer:</h3>
The New pressure (750 mmHg) is greater than the original pressure (500 mmHg) hence, the new volume (6.0 mL) is smaller than the original volume (9.0 mL).
<h3>Solution:</h3>
According to Boyle's Law, " <em>The Volume of a given mass of gas at constant temperature is inversely proportional to the applied Pressure</em>". Mathematically, the initial and final states of gas are given as,
P₁ V₁ = P₂ V₂ ----------- (1)
Data Given;
P₁ = 500 mmHg
V₁ = 9.0 mL
P₂ = 750 mmHg
V₂ = ??
Solving equation 1 for V₂,
V₂ = P₁ V₁ / P₂
Putting values,
V₂ = (500 mmHg × 9.0 mL) ÷ 750 mmHg
V₂ = 6.0 mL
<h3>Result:</h3>
The New pressure (750 mmHg) is greater than the original pressure (500 mmHg) hence, the new volume (6.0 mL) is smaller than the original volume (9.0 mL).
Answer: Gold.
Explanation: Water, CO2, and table salt are compounds. They are composed of two or more separate elements; a mixture, where as gold is neither.