Answer: NOT accurate, but precise.
[translation: You screwed up, but did it in style].
Explanation:
The average mass measurement is 41.95g. Compared to the actual value of 28.0 grams, the measurement is NOT accurate.
The standard deviation for the data is 0.112. Dependiong on your definition of precision, this looks relatively good. I would go for precise.
SI unit of length - meters
120 grams of NaOH means 3 Moles of NaOH because 40 grams (Molecular Weight in grams) is one mole of NaOH.
Each mole of any substance contain Avogadro’s number of molecules ie., 6.022 x (10 to the power 23).
Hence 3 Moles of NaOH contain 3 times of Avogadro’s number of molecules ie., 3 x 6.022 x (10 to the power 23)
Answer:
1.89 g CaCO₃
Explanation:
You will have to use stoichiometry for this question. First, look at the chemical equation.
Na₂CO₃ + CaCl₂ ==> 2 NaCl + CaCO₃
From the above equation, you can see that for one mole of Na₂CO₃, you will produce one mole of CaCO₃. This means that however many moles of Na₂CO₃ you have in the beginning, you will have the same amount of moles of CaCO₃, theoretically speaking.
So, convert grams to moles. You should get 0.0189 mol Na₂CO₃. This means that you will get 0.0189 mol CaCO₃. I'm not sure what units you want the answer in, but I'm going to give it in grams. Convert moles to grams. Your answer should be 1.89 g.
I would honestly say C. All others have ingredients in them that makes them work, the combination of stuff to put out the fire, film is made from a certain material and drugs are an ovbious mixture. Looking at the stars is the only thing you don't need chemistry for.
