20 points!! Which numerical setup can be used to calculate the heat energy required to completely melt 100. grams of H2O(s) at 0°C?
A) (100. g)(334 J/g)
B) (100. g)(2260 J/g)
C) (100. g)(4.18 J/g•K)(0°C)
D) (100. g)(4.18 J/g•K)(273 K)

Zoe is investigating the composition of substance a, an unknown substance. using chemical processes, she analyzes substance a and determines it is composed of sodium, oxygen, and hydrogen atoms in a ratio of 1 : 1 : 1. what is substance a? a. a compound b. an element c. a heterogeneous mixture d. a homogeneous mixture

How many moles of air are there in a human lung with a volume of 2.4 l at stp? explain your answer

Asample of air with a volume of 2.20m3 at a pressure of 105 kpa and a temperature of 30c is cooled to 10c and the pressure is reduced to 75.0 kpa. what is the new volume? 6.9 1.34 2.56 43.0 2.88