Answer:
Chemical indicator, any substance that gives a visible sign, usually by a colour change, of the presence or absence of a threshold concentration of a chemical species, such as an acid or an alkali in a solution. An example is the substance called methyl yellow, which imparts a yellow colour to an alkaline solution.
Explanation:
Answer:
mass of carbon-dioxide = 0.262 g
Explanation:
Firstly, write the chemical equation of the reaction and balance the equation accordingly.
2NaHCO3(aq) → CO2(g) + H2O(l) + Na2CO3(aq)
Calculate the molecular mass of baking soda
molar mass of baking soda = 23 + 1 + 12 + 48 = 84 g
2 moles of baking soda = 2 × 84 = 168 g
molar mass of CO2 = 12 + 32 = 44 g
if 168 g of baking soda produces 44 g of carbon-dioxide
1 g of baking soda will produce ? grams of carbon-dioxide
cross multiply
mass of carbon-dioxide = 44/168
mass of carbon-dioxide = 0.2619047619
mass of carbon-dioxide = 0.262 g
Yes the ANSWER is Correct-
On first half life the mass will be 10 gram
On second half life the mass will be 5 gram
On third half life the mass will be 2.5 gram
Answer:
Kinetic energy of electron = -E₂ = 3.4 ev
Kinetic energy of electron = -E₄ = 0.85 ev
Explanation:
In case of hydrogen atom energy associated with nth state is,
En = -13.6/n²
For n = 2
E₂ = -13.6 / 2²
E₂ = -13.6/4
E₂ = -3.4 ev
Kinetic energy of electron = -E₂ = 3.4 ev
For n = 4
E₄ = -13.6 / 4²
E₄ = -13.6/16
E₄ = -0.85 ev
Kinetic energy of electron = -E₄ = 0.85 ev
