A. making an observation.
Explanation:
When scientists use one of their five sense to gather information, they are simply making an observation.
Most physical properties of matter are studied using sense of taste, of feel, sight, hearing and smell.
- Observation is the act of making a measurement or studying.
- It helps to investigate particular phenomenon in nature.
- Most observations made with our senses are usually qualitative in nature.
- They cannot be assigned values like quantitative ones.
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HA is a weak acid so there should be little amount of HA and then H+ and A- in the beaker so the last one is true a weak acid never converts completely to H+ and A-
Molar mass of empirical formula = 172.8 g/mole
346.6g/172.8 g/mole = 2.00 moles
Molecular formula = C2H2Br4