Answer:
There are five signs of a chemical change:
Colour Change.
Production of an odour.
Change of Temperature.
Evolution of a gas (formation of bubbles)
Precipitate (formation of a solid).
Answer:
Ksp = 0.1762
Explanation:
Applying
a) moles of HCl added, n= CV=0.5×0.012 = 6×10-3mol
b) since 0.006mol is present in 0.012dm3 of HCl
It implies moles of borax
C) Concentration = 0.706M
Ksp = [0.5]^2[0.706]= 0.176
Answer:
alkali metals
Explanation:
they all react vigorously or even explosively with cold water, resulting in the displacement of hydrogen.
Answer:

Explanation:
C = Allowable concentration = 1.1 mg/L
= Flow rate of river = 
= Discharge from plant = 
= Background concentration = 0.69 mg/L
= Maximum concentration that of the pollutant
The concentration of the mixture will be

The maximum concentration that of the pollutant (in mg/L) that can be safely discharged from the wastewater treatment plant is
.
Answer:
The answer to your question is
1.- 1.686 x 10²⁴ atoms
2.- 0.25 moles
Explanation:
1.-
1 mol ---------------- 6.023 x 10²³ atoms
2.8 moles ---------- x
x = (2.8 x 6.023 x 10²³) / 1
x = 1.686 x 10²⁴ atoms
2.- 1 mol ------------------ 6.023 x 10 ²³ molecules
x moles ------------- 1.50 x 10²³ molecules
x = (1.50 x 10²³ x 1) / 6.023 x 10²³
x = 0.25 moles