Answer:
The false statement is :
- Pyrite is an ore of gold and is used in jewelry making.
- Cobalt is not used in medicine.
Explanation:
Pyrite is an ore of iron sulfide found on the Earth and in coal, limestone and in many deposits of metallic ores. Due to its luster and pale yellowish color it appears as gold due to which it is also termed as Fool's gold.
It is used in firearms , in production of sulfur dioxide gas, etc.
Cobalt is used as medicine to treat cancer patient. Co-60 is used in treatment of cancer in which gamma rays produced by Co-60 are used to kill tumor cells in a cancer patient.
Where as talc is used in industries like : paper making, food, paints, plastics etc. Quartz is primary material used to prepare glass and cobalt is used as
Concentration = 2.14 âś• 10-2 m
For [Br-], there are 2 ions so 2 x 2.14 x 10^-2 =4.28 x 10^-2
Ksp = [Pb][Br]^2 = 2.14 âś• 10-2 x (4.28 x 10^-2 )^2 = 39.20 x 10^-6
Ksp = 3.92 x 10^-5
I believe the correct answer from the choices listed above is option D. Catalysts lower the activation energy of a chemical reaction. It <span>is a substance which speeds up a reaction, but is chemically unchanged at the end of the reaction. It provides another pathway for the reaction to occur.</span>
Answer:
B and BBr3
Explanation:
1) 3HBr + B = BBr3 + H2 (double all equation because H2)
2) 6HBr + <em>2B </em>= <em>2BBr3</em> + 3H2
Well you know that you have to balance out the equation to 0. So if I is -1 and Ca is +2 you know that I had to equal to -2. So you can do that by having two of them. So Ca=+2 and I2=-2 so CaI2 would equal 0 meaning that would be the correct answer. Hope that I explained that correct :)
