A. the wax is a both; 1. physical change-solid to liquid.
2. chemical change- burned to CO2 + H20 + heat + carbon as seen as black on the rod
b. the wick is neither; the wick does not change, just provides conduit for wax to flame
c. the glass rod is physical change; the carbon is only deported
HOPE THIS HELPS, IVE ALSO LEARNING BEEN LEARNING THIS RECENTLY
Answer: 5.47m/s
Explanation:
Mass = 72.3kg
K.E = 1080.0J
V =?
K.E = 1 /2MV^2
V^2 = 2K.E /M = (2x1080)/72.3
V = sqrt [(2x1080)/72.3]
V = 5.47m/s
The energy change if 84.0 g of CaO react with excess water is 98KJ of heat is released.
calculation
heat = number of moles x delta H
delta H = - 65.2 Kj/mol
first find the number of moles of CaO reacted
moles = mass/molar mass
the molar mass of CaO = 40 + 16= 56 g/mol
mass = 84 g
moles therefore = 84 g/56 g/mol =1.5 moles
Heat is therefore = 1.5 moles x -65.2 = - 97.8 Kj = -98 Kj
since sign is negative the energy is released
3 mass number- proton number
Answer:
4.22
Explanation:
pH stands for potential hydrogen. The letter “p” denotes potential and the letter “H” denotes hydrogen.
pH helps to find the acidity or alkalinity of an aqueous solution.
The number of hydrogen ions (protons) present in a solution is determined by the pH scale.
A pH greater than 7 makes the water more alkaline and a pH less than 7 makes the water more acidic.
![pH=-\log [H^+]=-\log [0.00006]=4.22](https://tex.z-dn.net/?f=pH%3D-%5Clog%20%5BH%5E%2B%5D%3D-%5Clog%20%5B0.00006%5D%3D4.22)
