When a chemical reaction involves the production of a gas, the mass of the gas is not included in the mass of the products. true or false

Why does a plastic bottle that is sealed at a high altitude change it’s shape when taken to lower altitude

Scientists are often interested in knowing the molar heat of combustion – the heat released during the combustion of one mole of a substance. use the periodic table to find molar masses. how many moles of ethanol are present in the sample?

Acompound has the molecular formula c3h8. which class of organic compounds does it belong to?