Why do scientific experiments need controls?

When the volume changes from 63.5 mL to 69.2 mL, what is the final pressure if the initial pressure was 735 mmHg pressure? law used?

A molecule that dissociates in water and gives off hydrogen ions is

How many moles of MgS2O3 are in 201g of the compound?

Which type of chemistry would deal with models of reactions?

What percent of the human body is water

Which physical method can be used for obtaining a sample of salt from a small beaker of salt water? boiling freezing chromatography sorting

Science is a unique field of thought because it relies on to describe the world. •Observations and experim •Teachers and students •Books and writings •Scientists and statements

Hemoglobin, a protein in red blood cells, carries o2 from the lungs to the body's cells. iron (as ferrous ion, fe2+) makes up 0.33 mass % of hemoglobin. if the molar mass of hemoglobin is 6.8 Ã 104 g/mol, how many fe2 + ions are in one molecule?

What could you predict about a methane molecule that would most likely be made by using both the quantum model of the atom and John Dalton's model?

What is the molar mass of an unknown hydrocarbon whose density is measured to be 1.97 g/l at stp?