The question is in complete, the complete question is:
Which element has an outer electron configuration of s
2
p4
?
(A) Ca (B) Cr (C) Ge (D) Se
Answer:
(D) Se
Explanation:
The outer electronic configuration of an atom reflects the group to which it belongs in the periodic table. Each group has its unique outermost electron configuration and number of electrons found in the outermost shell of the atoms of elements in the group.
s
2
p4 is the unique outermost electron configuration of group 16 elements. Group 16 elements have six electrons in their outermost shell. If we consider the options, only Se is a member of group 16. Hence it is only Se that has the outermost electron configuration s
2
p4
.
Answer: The enthalpy change for formation of butane is -125 kJ/mol
Explanation:
The balanced chemical reaction is,
The expression for enthalpy change is,
![\Delta H=[n\times H_f{products}]-[n\times H_f{reactants}]](https://tex.z-dn.net/?f=%5CDelta%20H%3D%5Bn%5Ctimes%20H_f%7Bproducts%7D%5D-%5Bn%5Ctimes%20H_f%7Breactants%7D%5D)
Putting the values we get :
![\Delta H=[4\times H_f_{CO_2}+5\times H_f_{H_2O}]-[1\times H_f_{C_4H_{10}}+\frac{13}{2}\times H_f_{O_2}]](https://tex.z-dn.net/?f=%5CDelta%20H%3D%5B4%5Ctimes%20H_f_%7BCO_2%7D%2B5%5Ctimes%20H_f_%7BH_2O%7D%5D-%5B1%5Ctimes%20H_f_%7BC_4H_%7B10%7D%7D%2B%5Cfrac%7B13%7D%7B2%7D%5Ctimes%20H_f_%7BO_2%7D%5D)
![-2877=[(4\times -393)+(5\times -286)]-[1\times H_f_{C_4H_{10}}+\frac{13}{2}\times 0]](https://tex.z-dn.net/?f=-2877%3D%5B%284%5Ctimes%20-393%29%2B%285%5Ctimes%20-286%29%5D-%5B1%5Ctimes%20H_f_%7BC_4H_%7B10%7D%7D%2B%5Cfrac%7B13%7D%7B2%7D%5Ctimes%200%5D)
Thus enthalpy change for formation of butane is -125 kJ/mol
Answer:
1.5
Explanation:
Given that :
Compound A and B are formed from Sulfur + Oxygen.
Compound A :
6g sulfur + 5.99g Oxygen
Compound B:
8.6g sulfur + 12.88g oxygen
Comparing the ratios :
Compound A:
S : O = 6.00 : 5.99
S/0 = 6.0g S / 5.99g O
Compound B :
S : O = 8.60 : 12.88
S / O = 8.60g S / 12.88g O
Mass Ratio of A / mass Ratio of B
(6.0g S / 5.99g O) ÷ (8.60g S / 12.88g O)
(6.0 g S / 5.99g O) × (12.88g O / 8.60g S)
(6 × 12.88) / (5.99 × 8.60)
= 77.28 / 51.514
= 1.50017
= 1.5
D) solid because they have the strongest forces of attraction b/w the molecules.
Answer:
6.3moles
Explanation:
The balanced chemical equation for the decomposition of phosphorus oxychloride (POCl3) is as follows:
POCl3 → POCl + Cl2
Based on the above decomposition reaction, it shows that;
1 mol of POCl3 will decompose to give 1 mole of Cl2
Hence, 6.3 moles of POCI3 will give 6.3 moles of Cl2.
