Its 3, because you cant filter out or evaporate an element from a compound, for example water mixed with sand is a ''mixture and the sand can be filtered out, or water with dissolved sugar is also a 'mixture' and the water can be evaporated.
Answer:
See explanation
Explanation:
Dilution law= C1V1=C2V2.
Where C is the concentration in mol per dm cube and V= volume in dm cube.
From the questions the parameters given are; V= 42.5ZmL, concentration or molarity of HCl= 0.193M and the molarity of KOH = 0.125M.
(a). At 0mL where the base KOH has not been added yet.
Moles of HCl = molarity × volume.
Moles of HCl = 0.193 × 42.5/1000
Moles of HCl= 0.00820205
pH=- log 0.0082025
pH= 2.086
Approximately, pH=2.1.
(b). At 3mL of 0.125M KOH
3/1000 × 0.125 mol/L
= 0.003L× 0.125 M
= 0.000375 moles KOH
Determining the number of moles of HCl, we have;
42.5/1000 × 0.193 mol/L
= 0.0082025
Final volume= 3mL+42.5mL= 45.5 ml
Final[HCl] = 0.0082025 - 0.000375 = 0.0078275.
Therefore, 0.0078275/ 0.0455
= 0.1720
pH= -log 0.1720
pH= 0.76.
(c). 5mL of 0.125M KOH
5/1000 × 0.125
= 0.005×0.125
= 0.000625 mol KOH
42.5/1000 × 0.193 mol/L
= 0.0082025 mol
Final volume= 5mL + 42.5= 47.5 mL.
0.0082025-0.000625= 0.0076
Final [HCl] = 0.0076/0.0475
= 0.16
pH= -log 0.16
pH= 0.79.
Answer:
C. digestive; circulatory
Explanation:
It is the correct answer..
I think the answer is D
It replaces the element alone with an element next to another element. A+BC ->AC+B
