Answer:
It is mentioned that the student is mixing chemicals A and B and observes the time taken for the color to change. However, in the experiment, it is noticed that the student has repeated the procedure five times and each time he or she is modifying the concentration of chemical B. Thus, it is clear that the concentration of chemical B is the independent variable in the experiment. An independent variable is illustrated as the variable, which is controlled or modified in the experiment.
The pressure of the gas : 1.1685 atm
<h3>Further explanation</h3>
In general, the gas equation can be written

where
P = pressure, atm
V = volume, liter
n = number of moles
R = gas constant = 0.08206 L.atm / mol K
T = temperature, Kelvin
n=moles=1.5
V=volumes = 30 L
T=temperature=285 K
The pressure :

Answer:
The answer is C) The temperature at which the solid-state turns into liquid
Explanation:
The melting point of a substance is the temperature at which it shifts state from solid to liquid. At the melting point, the solid and liquid levels exist in equilibrium. As heat is applied to a solid, its temperature will increase until the melting point is reached. More heat then will convert the solid into a liquid with no temperature change. This occurs when the internal energy of the solid increases, commonly by the application of heat or pressure, which increases the substance's temperature to the melting point.
The equilibrium reaction, causes the water dissociation constant, Kw, is 1.01 × 10-14<span> at 25 °C. That is because every H</span>+<span> (H</span>3O+) ion these forms accompanied by the formation of an OH-<span> ion, are the concentrations of these ions and in pure water the same thing can be calculated from </span>Kw<span>.
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