In which region is the substance in both the solid phase and the liquid phase ?
2
Answer: The correct option is The properties of a noble gas.
Explanation: There are 7 periods in the periodic table.
The last element of each period are Helium (He), Neon (Ne), Argon (Ar), Krypton (Kr), Xenon (Xe), Radon (Rn) and Ununoctium (Uuo).
- The electronic configuration for Helium is
. For He, The outermost electrons are 2.
- The electronic configuration for all the other elements is
( where, n = 2, 3, 4, 5, 6 and 7 respectively). For all the other gases, the outermost electrons are 8.
All these elements have stable electronic configuration and are not reactive in nature. Hence, they are considered as noble gases.
Therefore, the last element of each period always have the properties of a noble gas.
Answer:
Explanation:
Bromine >Tellurium > Phosphorus > Helium > Sodium
Electron affinity of Bromine , Tellurium , Phosphorus are positive , of helium is zero and of sodium is negative .
Answer:
HCl
Explanation:
Given data:
Mass of Zn = 50 g
Mass of HCl = 50 g
Limiting reactant = ?
Solution:
Chemical equation:
Zn + 2HCl → ZnCl₂ + H₂
Number of moles of Zn:
Number of moles = mass / molar mass
Number of moles = 50 g/ 65.38 g/mol
Number of moles = 0.76 mol
Number of moles of HCl:
Number of moles = mass / molar mass
Number of moles = 50 g/ 36.5 g/mol
Number of moles = 1.4 mol
Now we will compare the moles of Reactant with product.
Zn : ZnCl₂
1 : 1
0.76 : 0.76
Zn : H₂
1 : 1
0.76 : 0.76
HCl : ZnCl₂
2 : 1
1.4 : 1/2×1.4 = 0.7
HCl : H₂
2 : 1
1.4 : 1/2×1.4 = 0.7
Less number of moles of product are formed by HCl it will act limiting reactant.
