Answer:
Mass = 15.1 g
Explanation:
Given data:
Number of moles of NaBH₄ = 0.40 mol
Mass in gram = ?
Solution:
Formula:
Mass = number of moles × molar mass
Molar mass of NaBH₄ = 37.83 g/mol
By putting values,
Mass = 0.40 mol × 37.83 g/mol
Mass = 15.1 g
The symbol of the period five element that is a member of the pnicitides family are antimony.
Explanation:
Pnictogen family
- In periodic table, column 15 elements are Pnitogen family.
- The pnictogen elements are Nitrogen-N, arsenic-As, phosphorus-P, bismuth-Bi, antimony-Sb, ununpentium-Uup.
- There are five valence electrons each member of pnictogen family. In group 15 double bonds and triple bonds are formed due to these valence electrons.
- Pnictides, binary compounds of group 15.
Antimony
- Antimony is the element found in period 5 and block p.
- A chemical element, Antimony (Sb) from Latin word stibium and 51 is its atomic number. It is in solid state.
- In ancient times, antimony compounds are used as cosmetic and medicine.
- Appeared as semi metal.
- Electronic configurations of Sb is [Kr] 4d105s25p3.
freezing. Think of what happens when you put water in the freezer
1) To find the change in enthalpy, determine the difference between the potential energy of the products and the potential energy of the reactants. (on this diagram, C-A) To find the activation energy, find the difference between the potential energy of the reactants and the "peak" of the curve (on this diagram, B-A). For this diagram, both the enthalpy and activation energy are positive.
2) If the reaction was exothermic, enthalpy would be negative, and the potential energy of the reactants would be greater than the potential energy of the products.
Explanation:
Ok so water is H2O and cabon dioxide in the air is CO2, so the water goes through the carbon dioxide and makes acid rain H2SO4.
Now we have our limestone which is CaCO3.
What happens is that the acid breaks apart our limestone into Ca2+ and CO3 2-. This then reforms into Calcium bicarbonate Ca(CO3)2.
Calcium bicarbonate is soluble in water and is hence washed away by the rain eroding the limestone.
