Question

questions 9,10 and 11 please! thank you

lying 0.23 mol of hypochlorous acid and 0.27 mol of sodium fent to yield 1.00 L of solution. The addition of 0.05 mol of NaOH to this to increase slightly. The pH does not increase drastically because the present in the buffer solution. The Ka of hypochlorous acid is A solution is prepared by dissolu hupachlorite in water sufficien buffer solution causes the pH toinen NaOH reacts with the 30.10-8 Ohypochlorous acid B) H2O hypochlorite D) H30+ solution: the pH does not change upon addition of acid or base. E) This is a buffer solution: 10) A water sample tested posi is 1.00 g/mL. Which of the follo tested positive for lead with a concentration of 47 ppm. The density of the solution Which of the following statements is correct? here are 47 mg of lead in 1.0 L of this solution B) the molarity of the solution is 47 M C) the solution is 47% by mass of lead D) 100 g of the solution contains 47 g of lead E) 100 g of the solution contains 47 mg of lead INSWER. Write the word or phrase that best completes each statement or answers the question. 11) The dopant atoms in an material. semiconductor have more electrons than the host 11)_ B-2

Answer 1

9) answer : A)

on addition of NaOH, OH- react with acid and gets neutralized

OH-   + HClO ------------------> ClO- + H2O

here ClO- is the part of buffer . so there is no change in pH

10)   answer :   A)

reason is that ppm means mg / L . here 47 ppm is given it indicates that 47 mg of Pb is present in 1.00 L of solution

ppm   = mg / L

11) answer : N- type

reason : in N-type semiconductors there are more electrons and

               in p-type semiconductors there are more holes

these are carriers in N-type and P-type semiconductors