The question is incomplete, here is the complete question:
A chemist adds 180.0 mL of a 1.42 M sodium carbonate solution to a reaction flask. Calculate the mass in grams of sodium carbonate the chemist has added to the flask. Be sure your answer has the correct number of significant digits.
<u>Answer:</u> The mass of sodium carbonate that must be added are 40.9 grams
<u>Explanation:</u>
To calculate the mass of solute, we use the equation used to calculate the molarity of solution:
Molar mass of sodium carbonate = 106 g/mol
Molarity of solution = 1.42 M
Volume of solution = 180.0 mL
Putting values in above equation, we get:
Hence, the mass of sodium carbonate that must be added are 40.9 grams
Answer:
Phenolphthalein is a chemical compound with the formula C20H14O4 and is often written as "HIn" or "phph" in shorthand notation. Phenolphthalein is often used as an indicator in acid–base titrations. For this application, it turns colorless in acidic solutions and pink in basic solutions.
<h3><u>Answer;</u></h3>
C) A convex lens has a thick center and thin edges; a concave lens has a thin center and thicker edges.
<h3><u>Explanation;</u></h3>
- Convex lens refers to the lens which merges the light rays at a particular point, that travels through it, while a concave lens can be identified as the lens which disperses the light rays around, that hits the lenses.
- A convex lens is thicker at the center, as compared to its edges, while a concave lens is thinner at the center as compared to its edges.
- A concave lens is thicker at the edges than in the middle and spreads light rays apart producing an image smaller than the actual object. A convex lens on the other hand, is thinner at the edges and thicker towards the center, that is they are bent towards a central point.
