Answer:
D) 10.812
Explanation:
Given:
The two isotopes of boron (B).
Boron-10 has an abundance of 19.8% and Boron -11 has an abundance of 80.2%
To find:
The atomic mass of europium.
Solution:
Mass of Boron-10 = 10.013 amu
The percentage abundance of Boron-10 = 19.8%
The fractional abundance of Boron-10 =0.198
Mass of Boron-11 = 11.009 amu
The percentage abundance of Boron-11= 80.2%
The fractional abundance of Boron-11= 0.802
The average atomic mass of Boron = A.M
A.M = Mass of isotope x Fractional abundance of isotope
= 10.013amu x 0.198 +11.009amu x 0.802 = 10.81u
Therefore, D) 10.812 amu is the atomic mass of boron.
Explanation:
The dissociation constant of the water is given as :
The value of st 25°C =
Water is neutral in nature with equal amount of hydronium and hydroxide ions.
The pH of the water at 25°C is 7.
With increase in temperature dissociation of water will increase with which concentration of hydronium and hydroxide ions will also increase which will in return will lower the down the pH of the water at higher temperature.
this is so ez,
ok so here what u'll do after u balance the equation:
1. convert grams of oxygen to moles of oxygen.
2. convert moles of oxygen to moles of water
3. convert moles of water to grams of water.
4. bOOm... that's your answer
as follows:
2H2O(l)===>2H2(g)+O2(g)
1. 151200(g)/16(g/mol)=9540 moles of O2
2. 9450 moles of O2 × 2 moles of H2O =18900 moles of H2O
3. 18900 moles of H2O × 10g/mol = 189000g of H2O is required.
The action produces heat energy.
Catalysts are used up during chemical reaction is the one statement among the following statements that is true about catalysts. The correct option among all the options that are given in the question is the third option or option "c". I hope the answer comes to your help.