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Chapter 10
Chapter 10: Chemical Quantities, vocab and key ideas
Question | Answer |
---|---|
How can you convert amoung the count, mass and volume of something? | by knowing how the count, mass and volume relate to a common unit. |
What is a mole? | a unit that is a specific number of particles. |
What is the mole number or Avogardo's number? | 6.02 x10^23 |
The term representative particle refers to what? | the species present in a substance (usually an atoms, molecules or formula units.) |
The representative particle for most elements is what? | the atom |
What does the mole allow chemists to do? | count the number of representative particles in a substance. |
What is the first step to find the number of atoms in a given number of moles of a compound? | first determine the sumber of representative particles. |
How do you convert the number of moles in a compound to the number of representative particles? | multiply the number of moles by 6.02 x 10^23 representative particles/one mole. |
How big is a mole? (the measurment) | HUGE |
How do you determine the molar mass of an element and of a compound? | 1)the atomic mass of an element is the mass of a mole of the element 2) find the number of grams of each element in one mole of the compound. Then add the masses of the elements in the compound. |
What was Avogadro's hypothesis? | that equal volume of gasses at the same temperature and pressure contain equal numbers of particles. |
Standard temperature and pressure stands for what? | STP |
What does standard temperature and pressure mean? | a temperature of degree 0 C and the pressure of 101.3 k Pa, or 1 atmosphere. |
The quantitly 22.4 is called what? | molar volume. |
Molar volume is used to convert between what? | between the number of moles of gas and the volume of gas at STP. |
What is percent composition? | the percent by mass of each element in the compound. |
What are the steps in finding the percent by mass of an element in a compound? | find the number of grams in an element, divide by the mass in grams of the compound, then multiply it by 100%. |
What does the empirical formula of a compound give? | the lowest whole-number ratio of the atms or moles of the elementin a compound. |