What is the pH of a 0.75 M solution of NaCN? Note: The Ka of HCN is 4.9 × 10⁻¹⁰. Hint: NaCN dissociates 100% in water and acts as a weak base. This is therefore a weak base pH calculation. 

At 25°C, the pH of a solution is 8.43.  Which of the following statement is FALSE about this solution?   

Which of the following solutions of weak acid would have the highest pH at 25°C? Hint: This is not a calculation problem. Consider the relationship between Ka, percent of ionization and solution pH. 

Based on the chemical structure, which of the following will be the weakest acid?

Based on the chemical structure, which of the following solutions would have the lowest pH? Hint: Assume equimolar concentrations for all solutions. Weakest acid or strongest base would have the highest solution pH.  

What is the pH of a 0.20 M solution of NaF? Note: The Ka of HF is 6.8 × 10⁻4. Hint: NaF dissociates 100% in water and acts as a weak base. This is therefore a weak base pH calculation. 

At 25°C, the pH of a solution is 5.41.  Which of the following statement is TRUE about this solution?   

Which of the following solutions of weak acid would have the smallest percent ionization at 25°C? Hint: This is not a calculation problem. Consider the relationship between Ka, percent of ionization and solution pH. 

  What is number 4 in the figure below: :

Consider the following MongoDB query: db.employees.updateOne( { name: “John Smith” }, { $inc: { salary: 5000 }, $set: { department: “Engineering” } } )What will this query do?