Which of the following displays the correct change in enthalpy and best describes the reaction below? 2cscl(aq) + na2so4(aq) 2nacl(aq) + cs2so4(aq) given: cs2so4: ∆h= -1400 kj cscl: ∆h= -415 kj na2so4: ∆h= -1380 kj nacl: ∆h = -411 kj

This image is an example of a(n) a) atom. b) compound. c) mixture. d) molecule.

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

Upon decomposition, one sample of magnesium fluoride produced 1.65 kg of magnesium and 2.56 kg of fluorine. a second sample produced 1.32 kg of magnesium. part a how much fluorine (in grams) did the second sample produce?