Tính ph tại thời điểm khi thêm 50,0ml dung dịch KOH 0.050M vào 50,0ml dung dịch acid formic 0,050M. Cho biết Ka, HCOOH= 4,26 x 10-4

Calculate the change in entropy if br2(l) is converted to br2(g). s° for br2(l) = 152.2 j/(mol•k) s° for br2(g) = 245.5 j/(mol•k) s° for br(g) = 175.0 j/(mol•k)

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

Which characteristics can be used to differentiate star systems? check all that apply.