Giúp mình 2 câu này với ạ 1, Pha 500ml dung dịch HCl 10% (w/v) từ dung dịch 37% (w/w) d=1.19 g/ml
2, Cách pha như thế nào để nhận được 200g dung dịch HCl 25% (w/w) từ dung dịch HCL 37% (d=1.19 g/ml)

For ai it's atomic number is 13 and it's mass number is 27 how many neutrons does it have

Why is the bond angle in a water molecule less than the bond angle of methane? a. the central oxygen atom in water has two lone pairs of electrons, whereas the central carbon atom in methane has no lone pairs. b. the central hydrogen atom in water has one lone pair of electrons, whereas the central carbon atom in methane has two lone pairs. c. the central oxygen atom in water has four lone pairs of electrons, whereas the central carbon atom in methane has only one lone pair. d. the central oxygen atom exerts more repulsive force on surrounding atoms than the central carbon atom in methane does. reset next

The diagram below shows a cell placed in a solution.a cell is shown placed inside a beaker. it is labeled cell. the solution inside the beaker is labeled 40% salt solution and the solution inside the cell is labeled 20% salt solution.only water is allowed to move in and out of the cell. what will most likely happen to the cell? it will expand as water moves out of it. it will shrink as water moves out of it.it will expand as water moves into it. it will shrink as water moves into it.