There are six liquids found on the periodic table.
1. Bromine
2. Mercury
3. Caesium
4. Gallium
5. Rubidium
6. Francium
Answer:
0.005 mol
Explanation:
Moles is denoted by given mass divided by the molecular mass ,
Hence ,
n = w / m
n = moles ,
w = given mass ,
m = molecular mass .
From the question ,
w = given mass of Gold = 1.05 g ,
m = molecular mass of Gold = 197 g/mol
<u>Hence , moles can be calculated as -</u>
n = w / m
= 1.05 g / 197 g/mol = 0.005 mol
Answer:
Reactants, Activation energy, Energy released by the reaction and Products
Explanation:
This energy profile is that of an exothermic reaction. In an exothermic reaction, heat is liberated to the surrounding. The surrounding becomes hotter than the environment.
The first box to the left is the reactants which signifies the species combining together.
The topmost box is the activation energy which is the energy barrier that must be over come before a reaction takes place.
The box underneath is the energy change. Here, energy is being released.
The right most box is the product of the reaction.
Answer:
7.44x10⁻³ mol/L and 744 ppm
Explanation:
Let's assume that the hardness of the water is totally from Ca⁺² ions only(the hardness is the measure of Ca⁺² and Mg⁺² ions). The titration with EDTA will form a complex. The EDTA is always in 1:1 proportion, so the number of moles of it will be the number of moles of Ca⁺², which will be the number of moles of CaCO₃.
n = 0.0124 L * 0.0300 mol/L
n = 3.72x10⁻⁴ mol
The molarity is the number of moles divided by the volume (0.05 L)
M = 3.72x10⁻⁴/0.05
M = 7.44x10⁻³ mol/L
1 part per million = 1 mg/L. The molar mass of the CaCO₃ is 100 g/mol, so the mass of it is:
m = 3.72x10⁻⁴ mol * 100 g/mol
m = 0.0372 g = 37.2 mg
Then, the ppm:
37.2/0.05 = 744 ppm
