Please Help with 2. Thanks

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

Which of the following is most likely true about water in chemical solutions?

1.9 mol hcl and 3.9 mol naoh react according to the equation hcl + naoh −→ nacl + h2o . if the limiting reactant is hcl, calculate the amount of nacl formed.