KOH is an alkali metal hydroxide and so would be a strong base. HCl is a hydrogen halide in solution, which would be a strong acid (the exception would be HF). There are no other strong bases or acids in this list, so these two substances will comprise our bookends.
KNO3 is a salt produced during the neutralization reaction between KOH and HNO3; the former is (as we just noted) a strong base, and the latter is a strong acid. The salt consisting of the conjugate acid and base of a strong base and acid, respectively, produces a neutral solution in water. So, the KNO3 would be neutral.
KCN in solution consists of the ions K+ and CN-; K+, as we just went through, is the conjugate acid of KOH, a strong base. CN- is the conjugate base of HCN, a weak acid in solution. Since the resultant salt, KCN, is the neutralization product of a strong base and a weak acid, it will be slightly basic in solution (the CN- is a stronger base than K+ is as an acid). So, the KCN solution would be slightly basic.
NH4Cl dissociates in solution to give NH4+ and Cl-. NH4+, as the conjugate acid of the weak base ammonia, NH3, will donate an H+ in water. Cl- is the conjugate base of a strong acid, HCl. The neutralization product of a strong acid (HCl) and a weak base (NH3) would be slightly acidic. So, the solution of NH4Cl would be slightly acidic.
Ranking the solutions from most acidic to most basic (note: it’s important that the solutions have the same concentrations), we get:
HCl (strong acid)
NH4Cl (weak acid salt)
KNO3 (neutral salt)
KCN (weak basic salt)
KOH (strong base).
Answer:
7g/cm³
Explanation:
Given parameters:
Mass of the mineral = 21g
Volume = 3cm³
Unknown:
Density of the mineral = ?
Solution:
Density of a substance is the mass per unit volume of the substance.
Density =
Now insert the given parameters and solve;
Density = = 7g/cm³
The mineral with a density of 7g/cm³ is Galena, an ore of lead.
Barium peroxide is BaO2.
Hydrogen peroxide is H2O2
This reaction produces hydrogen peroxide from barium peroxide:
BaO2 + H2SO4 ---> BaSO4 + H2O2
So, 1 mol of BaO2 produces 1 mol of H2O2.
Convert 1.50 g of BaO2 to moles:
moles = mass in grams / molar mass
molar mass of BaO2 = 137g/mol + 2*16g/mol = 169 g/mol
moles of BaO2 = 1.50g / 169 g/mol = 0.00888 moles
Then, the same number, 0.00888, will be produced of H2O2.
Now convert 0.00888 moles of H2O2 to mass in grams:
mass in grams = number of moles * molar mass
molar mass of H2O2 = 2 * 1 g/mol + 2 * 16 g/mol = 34 g/mol
mass of H2O2 = 0.00888 moles * 34 g/mol = 0.30192 grams.
Rounded to 3 significant figures = 0.302 grams.
Answer: 0.302 grams
Answer:
₈₄Po²²⁰
Explanation:
₈₆Rn²²⁴ → ₈₄Po²²⁰ + ₂He⁴
In given decay reaction alpha particle is emitted from Radon.
Alpha radiations:
Alpha radiations are emitted as a result of radioactive decay. The atom emit the alpha particles consist of two proton and two neutrons. Which is also called helium nuclei. When atom undergoes the alpha emission the original atom convert into the atom having mass number 4 less than and atomic number 2 less than the starting atom.
Alpha radiations can travel in a short distance.
These radiations can not penetrate into the skin or clothes.
These radiations can be harmful for the human if these are inhaled.
These radiations can be stopped by a piece of paper.
Cave rock neutralizes pollutants in groundwater.