1. Calculate the heat of hydrogenation of ethane (C2H6) given the following thermochemical equations:
a. 2C (graphite) + 3 H2 (g) –> CzHe (g) AHfo = - 84.5 kJ/mol
b. 2C (graphite) + 2 H2 (g) -> C2H4 (9) AHfo = 52.3 kJ/mol

Afamily is one another name for a group on the table of elements.

Sarah wants to know where in her garden chamomile would grow the best. she thinks chamomile will grow best in the corner of the garden that gets the most sunlight. to test her hypothesis, she decides to plant several groups of chamomile in her garden as an experiment. which of the following variables will sarah need to measure to know which group of plants grew best? a. the location of the plants b. the type of plants c. the height of the plants d. the amount of water she gives the plants

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