Abase
a. has a low ph in solution.
b. turns blue litmus paper to red.
c. releases hydroxyl ions in solution.
d. releases hydrogen (or hydronium) ions in solution.

The correct option is c

Explanation:

A base is a substance that produces hydroxyl ion (OH⁻) as the only negative ion when dissolved in water. For example, NaOH (a base) dissociates in water as follows

NaOH(s)  → Na⁺(aq) + OH⁻(aq)

A base has a pH between 7-14. And a base turns red litmus paper to blue.

From the above, it can be deduced that option c is the correct answer. The remaining properties expressed in the other options are properties of an acid.

a mercury barometer is a device that uses the physical properties of mercury in a tube to measure barometric pressure. mercury barometers are used for : -

1. measurement of atmospheric pressure  

2. determining the altitude of a place

3. weather forecasting

4. calibration and checking of aneroid barometers

5. application in fluid mechanics

6. measurement of pressure in aircrafts

7. surface weather analysis

8. preparation of barographs

9. usage in physical sciences like physics, astronomy & chemistry

10. preparation of aircraft altimeters

characteristics of mercury barometer : -

1.used to define and measure atmospheric pressure.

2.on the average at sea level the column of mercury rises to a height of about 760 mm.

3.this quantity is equal to 1 atmosphere.

4.it is also known as standard atmospheric pressure.

5.a barometer in which the weight of a column of mercury in a glass tube with a sealed top is balanced against that of the atmosphere pressing on an exposed cistern of mercury at the base of the mercury column, the height of the column varying with atmospheric pressure.

the answer is the first option

explanation:

just googled it m8. not that hard

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