Choose the correct name for NiS2. 

The following image shows interactions between molecules of ethylamines (CH3CH2NH2). From the image identify the hydrogen bonds. 

Which of the following gases have the greatest root mean square velocity/speed?

Which of these ions has the largest radius (O2-, F-, Na+, or Mg2+)?

Using the data below on successive ionization energies, determine what the element could be?    Number of Electrons Removed  Ionization Energies (kJ/mol)   1  600  2  1200  3  3000  4  12,000  5  13,000  6  14,500  7  15,600 

Determine the amount of heat released (in kilojoules) when 12.20 grams of ethane, C2H6, undergoes combustion according to the following equation: 2C2H6 (g) + 7O2 (g)

Which of the following statement(s) is/are correct  Sample A can be a representation of a flask containing carbon monoxide gas.  Sample B can be a representation of a flask containing nitrogen dioxide gas. Sample C can be a representation of a flask containing helium gas and hydrogen gas. 

How many moles K3PO4 would be produced if 24 moles of KOH were used in the reaction? The balanced chemical equation is given below.                        3KOH  +  H3PO4 ⟶  K3PO4  +  3H2O

How many sigma and pi bonds are in the structure below?  

The reaction of solid silicon (Si) with gaseous oxygen can be used to produce silicon trioxide. How many grams of silicon trioxide are produced in the reaction when 4.25 g of silicon reacts with 3.75 g of oxygen gas?    2Si (s) + 3O2 (g)