An accepted and universally true explanation of observed facts is a law.
Heat can be calculated using the formula:
U = mCpΔT
where:
U = internal energy or heat
m = mass of substance
Cp = specific heat capacity of a substance (constant)
ΔT = change in temperature = (Tf - Ti)
In the problem, we are given all these terms except for the Cp, which can help identify what the substance is. This is because Cp is unique and constant for a particular substance.
9760 = 200(Cp)(45-25)
Cp = 2.44 J/g-°C
Now, look for a library or list of specific heat capacities. Look for a substance that has the closest value to what you calculated. Based on data, the substance used is ethyl alcohol which has a Cp of exactly 2.44 J/g-°C
You can use this as reference: http://www.engineeringtoolbox.com/specific-heat-capacity-d_391.html
Molarity of solution = 1.6 M
<h3>Further explanation</h3>
Given
40 g NaOH
6 L solution
Required
Steps to solve the problem of molarity
Solution
No additional information about the question.
If you want to make the solution above, then we just need to put the existing NaOH (40 g) into 6 L of water, then do the stirring (in a warm temperature above the hot plate will speed up the NaOH dissolving process)
But if you want to know the molarity of a solution, then
- 1. we calculate the moles of NaOH

MW(molecular weight) of NaOH=
Ar Na+ Ar O + Ar H
23 + 16 + 1 = 40 g/mol
so mol NaOH :


Not sure what you need to know, but if it’s true or false it would be false. it’s actually 174.26
Answer:
Explanation:
Question 1:
atomic number/number of protons
All atoms of the same element share the same number of protons or atomic numbers. In grouping elements on the periodic table, the periodic law is often used. The modern periodic law states that "properties of elements are a periodic function of their atomic number". The atomic number of an element distinguish it from others.
Question 2:
The two carbon atoms would be quite different as they are isotopes. Isotopy is the existence of two or more atoms of the same element having the same atomic number but different mass numbers due to the differences in the number of neutrons in their various nuclei.
Naturally, carbon exists in two isotopic forms:
¹³₆C and ¹⁴₆C
One might see these different samples in a rock and in the skin cells. They are simply isotopes. Isotopes have the same electronic configuration and hence similar chemical properties. Only their masses differ.