1. Moles Fe = 209.7 g/ 55.847 g/mol= 3.75
The ratio between Fe and CO is 2 : 3
Moles CO = 3.75 x 3 /2 = 5.63
<span>Mass CO = 5.63 mol x 28.01 g/mol= 157.7 g
2. </span><span />2Na + 2H2O --> 2NaOH + H2<span>atomic weight of sodium is 23 48.7/23 = 2.12 moles of sodium
2.12/2 x 24 = 25.44dm^3 hydrogen = 1.06 moles
so multiply it by Avogadro's number1.06 X 6.02x10^23 = 1.204x10^24 molecules of hydrogen
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Answer:
C. Independent variable
Explanation:
The independent variable in an experiment is the variable that the experimenter manipulates or changes in order to effect a measurable response in the dependent variable.
According to this question, an experiment is conducted to determine what concentration of disinfectant is most effective in killing bacteria. The independent variable is the CONCENTRATION OF DISINFECTANT because it is the variable being changed or manipulated.
The pipettes can basically be characterized into five grades. these grades includes the serological, disposable, repeat, single channel and multi-channel pipette. The guidelines for the usage of each of these pipettes differ. However, some instructions are common, such as the control of the flow of liquid. The index finger is used for the purpose of controlling the flow of the liquid from the pipette.
Hence, the answer is 'index finger'.
