1.61 x 104 molecules Od
2.26 x 1029 molecules
Oe
1.77 x 1029 molecules
Question 5 (1 point)
A 1.3 kg block of copper initially at 12°C is dropped into a large vessel of liquid nitrogen. The temperature of the liquid nitrogen is 70 K. Find
the amount of liquid nitrogen that boils away as the copper reaches 70 K. (c(copper) = 385 J/kg.°C, L(nitrogen) = 2 x 105 j/kg

Which of the following is true for the actual yield of a reaction? it is always calculated as a ratio. it is the yield from the excess reactant. it is the yield from the limiting reactant. it is always less than the theoretical yield.

Melting and boiling are endothermic processes. this means that these processes absorb energy from their surroundings in order to occur. use this information and the data you collected in the phase change gizmo to describe what happens to the temperature of water when you boil it, then explain why this result occurs.

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