Answer:
C, physical change
Explanation:
take a look at the equation. Next to each form of water do you see the little (g) and (l)? These represent the state of matter the water is in. So, the water is going from a gas to a liquid. The chemical compound is the same so its a physical change, not chemical, and it is reversible. You could change the liquid water back to the gas through evaporation. Endothermic has literally nothing to do with this equation so you can easily eliminate that answer choice.
Here we have to get the height of the column in meter, filled with liquid benzene which exerting pressure of 0.790 atm.
The height of the column will be 0.928 m.
We know the relation between pressure and height of a liquid placed in a column is: pressure (P) = Height (h) × density of the liquid (ρ) × gravitational constant (g).
Here the pressure (P) is 0.790 atm,
or [0.790 × (1.013 × 10⁶)] dyne/cm². [As 1 atm is equivalent to 1.013 × 10⁶ dyne/cm²]
Or, 8.002ₓ10⁵ dyne/cm².
density of benzene is given 0.879 g/cm³.
And gravitational constant (g) is 980 cm/sec².
On plugging the values we get:
8.002×10⁵ = h × 0.879 × 980
Or, h = 928.931 cm
Or, h = 9.28 m (As 1 m = 100 cm)
Thus the height will be 9.28 m.
Properties like atomic number, valency etc...
Hello!
The observation that would provide the best evidence that a chemical reaction occurred is that The baking soda and hydrochloric acid combined, and bubbles formed.
When baking soda (NaHCO₃) and Hydrochloric Acid (HCl) combine, the following reaction happens:
NaHCO₃ + HCl → NaCl + H₂O + CO₂(g)↑
The gaseous Carbon Dioxide (CO₂) generated in this reaction is the responsible for the bubbles. The releasing of this gas is an evidence that a chemical reaction occurred between NaHCO₃ and HCl.
Have a nice day!
