The definition of chemical is "any substances that has a definite composition." What does "definite composition" mean?

How many liters of NH3, at STP, will react with 16.2 g O2 to form NO2 and water

Calculate the mass units of. 25 mol of carbon - 12 atoms.

The conjugate acid of a particular halide has a pka = 3. a student wants to use this halide in a substitution reaction thinking it will have a good leaving group. can this student use this halide in a substitution reaction?

When heating a flammable or volatile solvent for a recrystallization, which of these statements are correct? More than one answer may be correct. a. You should not use an open flame to heat the solvent. b.

Non-metals are highly likely to form ionic bonds with non-metal true or false

Materials with small, connected pores are a. impermeable c. unsaturated b. permeable d. saturated

Which of the following work by Robert Hooke most likely impacted later scientists who developed the theory that all organisms are made of cells? a.

Who first established the heliocentric view

If measurements of a gas are 75l and 300 kilopascals and then the gas is measured a second Time and found to be 50L describe what had to happen to the pressure

The neritic zone is also called the: a. Intertidal zone c. Eutrophic zone b. Bathyal zone d. Subtidal zone