pure substances can be divided into two groups; elements and compounds
The correct answer is B. An observation
Explanation:
An observation is defined as a statement or conclusion you made after observing or measuring a phenomenon, this includes statements based on precise instruments. For example, if you conclude a plant grows 2 inches every month by measuring the plant during this time, this is classified as an observation. The conclusion of the student is also an observation because he concludes this after analyzing the volume of the water in the cylinder through the lines in the graduated cylinder, considering the water is just in the middle of 100 mL and 200 mL which indicates there are 150 mL of water.
240 g NaOH
<em>Step 1</em>. Calculate the moles of NaOH
Moles of NaOH = 0.750 L solution × (8 mol NaOH/1 L solution) = 6 mol NaOH
Step 2. Calculate the mass of NaOH
Mass of NaOH = 6 mol NaOH × (40 g NaOH/1 mol NaOH) = 240 g NaOH
