Blog

Use these reactions:   to determine the ΔH rxn for the following reaction:   

Consider the compound etherium (II) bromate, Em(BrO3)2, where etherium, Em, is a made up element with a molar mass of [mm] g/mol. What is the mass percent of etherium in this compound? Note: Do NOT enter the % symbol in your answer.

All of the statements below about chemical bonding are correct except one. Which statement is false?

An unknown metal has a density of [d] g/mL. Consider a [V] mL sample of this metal. What is its mass in kilograms? Note: Do NOT include any unit symbols in your answer.

Decreasing the frequency of a source of electromagnetic radiation will _______ its wavelength and _______ its energy.

In which case does a dashed line correctly indicate a hydrogen bond between adjacent molecules?    

You dissolve [a] g of ThCl4 in water to make [b] mL of solution. What is the molarity of ThCl4 in this solution? Hint: Th is thorium, element #90. Note: Do NOT include any unit symbols in your answer.

How many protons, neutrons, and electrons are present in a neutral copper-65 (65Cu) atom?

What is the output of the following program: x = 18 if x % 2  == 0:  print(“x is even'”) else:   print(‘x is odd”)  

What does the following code print out? def thing(): print(‘Hey’)   print(‘you!’)