Explanation:
Some examples of colorful light emissions are street lights, neon signs and, of course, fireworks. Neon signs emit light when an electric current passes through the neon gas.
The specific heat capacity of this chunk of metal is equal to 0.32 J/g°C.
<u>Given the following data:</u>
- Quantity of energy = 400 Joules
- Initial temperature = 20°C
To determine the specific heat capacity of this chunk of metal:
<h3>
The formula for quantity of heat.</h3>
Mathematically, quantity of heat is given by the formula;
<u>Where:</u>
- Q represents the quantity of heat.
- m represents the mass of an object.
- c represents the specific heat capacity.
- ∅ represents the change in temperature.
Making c the subject of formula, we have:
Substituting the given parameters into the formula, we have;
Specific heat, c = 0.32 J/g°C.
Read more on specific heat here: brainly.com/question/2834175
The pH of a neutral aqueous solution at 37°C is 6.8.
<h3>What is Kw? </h3>
Kw is defined as the dissociation, which is also known as self-ionization, constant of water. this is an equilibrium constant, and its expression is:
Kw = [OH⁻] . [H₃O⁺]
Neutral pH determines that the concentrations of OH⁻ and H₃O⁺ are equal.
<h3>Calculation</h3>
Let us suppose concentration of OH and H₃O⁺ is x, to calculate it:
Kw =[OH⁻] . [H₃O⁺] = x²
x² = 2.4 × 10⁻¹⁴ M²
x = 1.5919 × 10⁻⁷ M
Hence, the concentration of OH and H₃O⁺ (x) = [H₃O⁺] = [OH⁻] = 1.5919×10⁻⁷ M
pH = -log[H₃O⁺] = -log( 1.5919×10⁻⁷ M)
pH = 6.8
Thus, we find that the pH of a neutral aqueous solution at 37 °c (which is the normal human body temperature) is 6.8.
learn more about pH:
brainly.com/question/9529394
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Answer: It is an exothermic process because heat energy is absorbed by the water as the NaOH(s) dissolves in it.
Explanation:
Endothermic reaction : It is a type of chemical reaction where the energy is absorbed from the surrounding. In the endothermic reaction, the reactant are less than the energy of product. In endothermic reaction, the change in enthalpy is, positive
Exothermic reaction : It is a type of chemical reaction where the energy is released into the surrounding. In the exothermic reaction, the energy of reactant are more than the energy of product. In exothermic reaction, the change in enthalpy is, negative.
Thus as energy is absorbed by water, which has been released by NaOH, the process is exothermic.
