Which is the correct Lewis structure for COF2?

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

Use the theoretical chemical symbol below to determine is corresponding statements are true or false.    Element Z has 710 protons.  [1] Element Z has 405 neutrons.  [2] Element Z has 307 electrons.  [3]  

Which of the following statement(s) about phase transitions is/are correct? Freezing refers to the phase transition from solid to liquid Sublimation refers to the phase transition from solid to gas. Vaporization refers to the phase transition from liquid to gas.

Which of the following compounds contains an exception to the octet rule on the central atom? SO3 [1] BF3 [2] NO2 [3]

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

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)

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

Which of the following statement(s) is/are correct?  S is the symbol for sodium Au is the symbol for gold O is the symbol for oxygen 

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