Answer:
The concentration the student should write down in her lab is 2.2 mol/L
Explanation:
Atomic mass of the elements are:
Na: 22.989 u
S: 32.065 u
O: 15.999 u
Molar mass of sodium thiosulfate, Na2S2O3 = (2*22.989 + 2*32.065 + 3*15.999) g/mol = 158.105 g/mol.
Mass of Na2S2O3 taken = (19.440 - 2.2) g = 17.240 g.
For mole(s) of Na2S2O3 = (mass taken)/(molar mass)
= (17.240 g)/(158.105 g/mol) = 0.1090 mole.
Volume of the solution = 50.29 mL = (50.29 mL)*(1 L)/(1000 mL)
= 0.05029 L.
To find the molar concentration of the sodium thiosulfate solution prepared we use the formula:
= (moles of sodium thiosulfate)/(volume of solution in L)
= (0.1090 mole)/(0.05029 L)
= 2.1674 mol/L
Answer:
The emission spectrum lines are the changes in the quantum energy levels of the single electron in the Hydrogen atom.
Explanation:
Electrons move around the hydrogen atom in electron waves patterns. These waves occur in distinct quantum energy levels.
The change from one quantum energy level to another energy level has a definite energy level change. There is a wave length associated with each change in energy levels. These wave lengths have a color associated with them.
Low energy level changes have long wave lengths associated with them giving red and orange colors.
High energy level changes have short wave lengths associated with them giving blue and violet colors.
Note each atom has a unique emission spectrum associated with the energy levels and electron structure of the atom. Helium was first discovered by looking at its emission spectrum as seen in the sun.
Explanation:
Answer:
Independent variable: DIFFERENT TEMPERATURE
Explanation:
The independent variable of an experiment is the variable that the experimenter changes or manipulates in order to effect an outcome or response in the measured variable/dependent variable.
In this experiment, a scientist wants to determine how temperature affects photosynthesis. He sets up the experiment by adding 20ml of water at different temperatures to three test tubes. Hence, the independent or experimental variable is the DIFFERENT TEMPERATURES GIVEN TO EACH PLANTS IN THE TEST TUBE because it is what the experimenter changes in order to effect a measurable outcome i.e. oxygen released in each balloon as a result of photosynthesis, which is the dependent variable
Answer:
I dont understand what is the question you need help on-
Explanation:
