Answer:
The Two reasons are :-
1. Combustion efficiency
2. Standardization of test conditions as non-luminous flame.
Explanation:
A luminous flame isn't suitable for heating as it gives out soot (A black powdery or flaky substance consisting largely of amorphous carbon, produced by the incomplete burning of organic matter)
For a given system, vapor pressure can be defined as the pressure exerted by the vapor phase in equilibrium with the condensed phase.
In this case, as water sits in an open beaker it tends to evaporate thereby forming water vapor. This vapor phase then exerts a pressure over the liquid water, which is termed as the vapor pressure of water at that temperature and pressure. As water continues to evaporate, more and more molecules escape into the vapor phase which thereby increases the vapor pressure.
Ans: The vapor pressure of water increases as the water evaporates.
Answer:

Explanation:
Helo,
In this case, the pressure must be computed as follows:

Which is using the density of mercury (13.6 g/mL) and its height, thus, we obtain (using the proper units):

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A mixture is a portion of matter made up of two or more substances called constituents. Mixtures are the product of the mechanical joining of substances without change in chemical nature, and therefore, each constituent retains its properties.
the option 4
Global wind patterns are mainly determined by unequal heating of the earth's surface, changes in air pressure, and earth's rotation. Change in air pressure: Air mainly circulates due to change in air pressure. It moves from a region of high air pressure to the region of lower air pressure.