I need these two questions answered will give Brainliest for them!! Combination of ∆H1, ∆H2, and ∆H3 needed (using Hess’s law):

The published value for this reaction is –603 kJ/mol. What is the percent error of your experimental value?

Select the correct answer. which statement is true about a polarized object? o a. it gains electrons and becomes negatively charged. ob. it gains protons and becomes positively charged. oc. the number of positive and negative charges can be the same. od. it has to be a metal. o e. there is no change in the distribution of the charge in the object. reset next what

A50.0g sample of liquid water at 0.0 c ends up as ice at -20.0 c. how much energy is involved in this change?

If we compare and contrast electromagnetic waves with sound waves, all but one statement is true. that is a) sound waves require a medium to travel while electromagnetic waves do not. b) electromagnetic waves can travel through the vacuum of space while sound waves cannot. c) electromagnetic waves must have a medium in which to travel, but sound waves can travel anywhere. eliminate d) sound waves must bounce off of matter in order to travel while electromagnetic waves do not require matter to be present.