Kamis, 25 Mei 2017

VIDEO ABOUT CHEMISTRY LEARNING

STOICHIOMETRY

What is stoichiometry?
            Stoichiometry is the basic chemical calculation that states quantitative relation of chemical formula and chemical equations. With stoichiometry you can calculate for examples; the mass, the mol, the volume, the percent, themperature, amount of molecul, amount of atom and another of thing.

Examples:
2,3 gram Natrium (Ar:23) included in 0.5 liter of HCl 0.1 M.

Question :
1. what is the chemical equations will be happen ?
2. how much mass of Natrium remainded ?
3. how much mass of NaCl produce ?
4. How much volume H2 in STP ?

Answers:
1. what is the chemical equations will be happen ?
     2Na + 2HCl -----à 2 NaCl + H2

2. how much mass of Natrium remainded ?
3. how much mass of NaCl produce ?
4. How much volume H2 in STP ?

The moll of natrium reacted :


Mol Na = mass / Mr                           Mol HCl = Volume x concentrate
       = 2,3 grm / 23                                             = 0.1 liter x 0.5 M
       = 0.1 mol                                                    = 0.05 mol


              2Na                +           2HCl       -----à             2 NaCl       +           H2
M        0,1 mol                         0,05 mol                              -                         -
R         2/2 x 0,05 mol              0,05 mol                         0,05 mol           ½ x 0,05 mol
S          0,05 mol                          -                                   0,05 mol              0,025 mol


2. how much mass of Natrium remainded ?
    The mass Na reacted is                                       The mass of Natrium remainded is
    Mass = mol x Mr                                                    2,3 grams – 1,15 grams = 1,15 grams
            = 0,05 mol x 23
            = 1,15 grams


3. how much mass of NaCl produce ?                       4. how much volume H2 in STP ?
     Mass = moll x Mr                                                      volume (STP) = moll x 22,4
             = 0,05 mol x 58,5                                                                      = 0,025 mol x 22,4

             = 2,925 grams                                                                            = 0,56 liter


For the video lets check this link :
https://youtu.be/bq7_KHgwma8

11 komentar:

  1. Can you explain why the mole reacts as much as 0.05

    BalasHapus
    Balasan
    1. Why the number of moles that reacts is only 0.05 mol because we know that the solution is basically exhausted because the mole of HCl is 0.05mol so that through the coefficient ratio of the reaction it was found that only 0.05 mol of Na reacted

      Hapus
  2. On your reaction equation, what is the number of molecules in the NaCl compound?

    BalasHapus
    Balasan
    1. The number of molecul in NaCl
      The mol x 6.022 x 10^23
      0.05 x 6.022 x 10^23
      0.3011 x 10^23
      3011 x 10^19 molecul

      Hapus
  3. For example in the combustion of FeS2 (Mr = 120) produced 2.24 liters of SO2 gas (STP) according to the reaction: FeS2 (s) + O2 (g) → Fe2O3 (s) + SO2 (g)

    How do we determine the required FeS2 mass

    BalasHapus
  4. How many way to calculate mol and please explain about it

    BalasHapus
    Balasan
    1. For example by the way

      1. the relationship of mol substances with the mass of matter

      Mass = mole x Mr

      2. through relationship with gas volume

      Hapus
  5. How to calculate a remain from one elements in your reaction?

    BalasHapus
    Balasan
    1. How to calculate how much the remaining substance tentunyankita must know in advance how number of mul react. In general the solution will react entirely so that we can do a coefficient comparison to find out how many moles it reacts.
      Of the reacting mole we can determine how much the mass reacts. From there we can calculate the remaining through the initial mass less the reacting mass.

      Hapus
  6. Is there a relationship between the rest of the reaction with stoichiometric calculation?please explain to me!

    BalasHapus
  7. can you explain about Consider the following reaction equation!
    Mg + 2HCl → MgCl2 + H2
    When 4 grams of Mg metal is introduced into 10 mL 2 M HCl solution, then the volume of H2 gas formed under standard circumstances is ...
    (Ar Mg = 24; H = 1; Cl = 35.5)

    When 4 grams of Mg metal is introduced into 10 mL 2 M HCl solution, then the volume of H2 gas formed under standard circumstances is ...
    (Ar Mg = 24; H = 1; Cl = 35.5)

    BalasHapus