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35 Cards in this Set
- Front
- Back
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What is the relative atomic mass? |
The weighted mean mass of an atom of an element compared with 1/12th the mass of an atom of C-12. |
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What is relatve molecular mass? |
The weighted mean mass of a simple covalent molecule compared with 1/12th the mass of an atom of C-12. |
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What is mole? |
The amount of substance containing as many particles as there are particles in exactly 12g of carbon 12. |
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What is molar mass? |
The mass, in g, per mole of a substance. Units are gmol-1. |
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How do you calculate amount in moles (n)? |
n=mass/Mr |
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What is avogadro constant |
The number of particles in one mole of any substance. |
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What is the symbol for avogadro constant? |
NA |
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What is the exact value of avogadros constant? |
6.02 x 10^23 |
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How would you calculate the number of particles in a substance? |
NA x Moles |
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What is empirical formula? |
The simplest whole number ratio of atoms of each element present in a compound. |
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What is molecular formula? |
The actual number of atoms of each element present in a compound. |
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What information do you need to calculate molecular formula? |
empirical formula relative molecular mass |
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What does hydrated mean? |
When all the waters of crystallisation are present in a compound. |
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What does anhydrous mean? |
When all the waters of crystallisation have been removed from a compound. |
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What does water of crystallisation mean? |
The water present in a compound giving it its crystalline appearance. |
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How would you work out the amount, in moles, of water in a crystal strucutre? |
1. Weigh empty crucible 2. Add hydrated salt to crucible and reweigh. 3. Heat the crucible to evaporate the water until anhydrous salt remains (constant mass) 4. Allow crucible to cool and reweigh. |
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How do ensure all the waters of crystallisation have been removed? |
heat to constant mass |
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How would salt be lost in experiment, how could you stop this? |
Spitting use glass woool. repeat and calculate a mean use a more accurate top pan balance |
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What is molar gas volume? |
The volume per mole of gas molecules at stated temperature and pressure. 24.0 dm^3 at rtp |
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How do you calculate the moles in a gas at rtp? |
n=volume(dm^3)/24dm^3 |
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what are the molecules deemed to be to make up ideal gas equation? |
radom motion elastic collisions (no energy lost) negligible size no intermolecular forces |
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What is idealgas equation? |
pV=nRT |
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What is p and what are units? |
pressure in Pa |
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What is V and what are units? |
volume m^£ |
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What is n and what are units? |
amount of gas in mole |
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What is R? |
gas constant 8.314Jmol^-1K^-1 |
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What is temperature measured in ideal gas equation? |
K (Kelvin) |
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How do you calculate the moles in solution? |
n=CV/1000 (if V is in cm3) |
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How do get from gdm^-3 to moldm^-3? |
x Mr |
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How do you make a standard solution? |
1. Accurately weigh the solid by difference by mass 2. Dissolve the solid in a beaker using a small amount of distilled water 3. Transfer the solution into the volumetric flask. Ensure you rinse the beaker and add to volumetric flask. 4. Carefully fill the flask until the meniscus lines up exactly with graduatin mark. 5. Invert flask several times |
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What is an acid base titration an example of? |
volumetric analysis |
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What needs to be a different colour in the acid solution to base solution? |
indicator` |
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What does a colour change in indicator show? |
end point |
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What is the final burette reading measured to? |
0.05cm3 |
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How often is a titration repeated? |
until two concordent results are achieved. (excluding trial) |
