Which of the following is not a substance?

1. methanol

2. milk

3. copper

4. water

A 1.80 g sample of barium chloride hydrate, BaCl2 ⋅ xH2O is treated with excess sulfuric acid, forming a BaSO4 precipitate which has a mass of 1.72 g. Calculate the value of x.

A model is any representation of an object or

In an effusion experiment it required 40 s for a certain number of moles of a gas of unknown molar mass to pass through a small orifice into a vacuum. Under the same conditions 16 s were required for the same number of moles of O2 to effuse.

At what concentration does sugar (covalent compound) conduct electricity?

Tin (II) fluoride (SnF2) is often added to toothpaste as an ingredient to prevent tooth decay. What is the mass of F in grams in 33.7 g of the compound?

Which describes an object's speed when free falling in a vacuum? The object accelerates until it reaches its terminal velocity. The object falls at a constant speed because only one force acts on it.

If you had 20,000 liters of NO2 how many moles would you have?

What does the name amino acid tell you about the structure of this molecule?

Fluorine is a toxic, reactive gas. which representation (structural formula, electron dot structure, or three-dimensional model) would you use to explain why fluorine is so reactive, why?

The electronic configuration of an element is given below. 1s22s22p63s1 Which statement about the reactivity of the element is true? It is reactive because it has a full outermost energy level.