Solution:
Part A) Correct option is 8.
The number of lewis dot in Ar = 8
Because Ar is a zero group element having inert configuration. It has eight valence electrons.
Part B) Correct option is: Ge ( Germanium)
There are four valence electrons. Hence, fourth period element is Germanium ( Ge).
Tutored Practice Problem 8.2.1 COUNTS TOWARDS GRADE Interpret Lewis symbols. (a) How many dots are there in the Lewis s...
Tutored Practice Problem 10.6.1 COUNTS TOWARDS GRADE Use and interpret standard heats of formation. (a) Write the balanced chemical equation that represents the standard heat of formation of Mgo(s) at 298 K. Use the pull-down boxes to specify states. Write fractions with a slash, such as 1/2 for one half. If a box is not needed leave it blank. (b) The standard enthalpy change for the following reaction is 2.14x103 kJ at 298 K. UF6(8)—U(S) + 3 F2(9) What is...
Tutored Practice Problem 15.2.2 COUNTS TOWARDS GRADE interconvert Kp and K. values. Calculate Kp for the following reactions at the indicated temperature. (a) PCl3(g) + C2g Kc-239 at 475 K (b) NH41(s)- NH3(g) + HI(g) K,-1.26x10-2 at 699 K Kp
Tutored Practice Problem 9.3.2 COUNTS TOWARDS GRADE Write net ionic equations for precipitation reactions Close Problem Write the net ionic equation for the precipitation reaction that occurs when aqueous solutions of cobalt(II) nitrate and ammonium carbonate are combined. Use the pull-down boxes to specify states such as (aq) or (8). If a box is not needed leave it blank. Check & Submit Answer Show Approach
Tutored Practice Problem 18.1.3 cOUNTS TOWARDS GRADE Use equilibrium ion concentration to calculate Ksp Close Problem The Pb2+ concentration in a saturated solution of lead chloride is measured and found to be 1.65x102 M. Use this information to calculate a K,p value for lead chloride. Ksp Check & Submit Answer Show Approach
Close Problem Tutored Practice Problem 19.3.1 COUNTS TOWARDS GRADE Calculate standard free energy change using AH and So values. Consider the reaction CH4(g) + H2O(g)—_>3H2(g) + CO(g) Calculate the standard free energy change for this reaction at 25°C from AHºrn and AS rxn: AGºrxn = kJ/mol Check & Submit Answer Show Approach
Tutored Practice Problem 19.3.4 COUNTS TOWARDS GRADE Calculate the equilibrium constant from the standard free energy change. Close Pr Using standard thermodynamic data (linked), calculate the equilibrium constant at 298.15 K for the following reaction. N2(g) + O2(g) +2NO(g) K- Check & Submit Answer Show Approach
Close Problem Tutored Practice Problem 4.3.2 COUNTS TOWARDS GRADE Write net ionic equations for precipitation reactions. Write the net ionic equation for the precipitation reaction that occurs when aqueous solutions of barium acetate and magnesium sulfate are combined. Use the pull-down boxes to specify states such as (aq) or(s). If a box is not needed leave it blank. Check & Submit Answer Show Approach
Tutored Practice Problem 16.4.1 COUNTS TOWARDS GRADE Predict and calculate the effect of concentration changes on an equilibrium system. Close Problem Some COCl2 is allowed to dissociate into CO and Cl2 at 873 K. At equilibrium, [COCI2] =0.237 M, and [CO] - [C12] = 0.128 M. Additional CO is added so that (CO)new = 0.193 M and the system is allowed to once again reach equilibrium. COC12(8) CO(g) + Cl2(g) K-6.98*10-2 at 873K (a) In which direction will the reaction...
Tutored Practice Problem 10.5.1 COUNTS TOWARDS GRADE Use Hess's law to calculate enthalpy change. Given the following two reactions: (1)Ca(s) + Cl2(9—+CaCl(s) AH(1) = -795.8 kJ (2)Hg(1) + Cl2(9) HgCl2(8) AH(2) = -224.3 kJ calculate the enthalpy change for the following reaction: (3) Ca(s) + HgC12(3)— CaCl2(S) + Hg(1) AH(3)=[ Check & Submit Answer Show Approach
Tutored Practice Problem 20.3.1 COUNTS TOWARDS GRADE Calculate standard free energy change using ΔHr and So values. Consider the reaction 4HCI(g) +02(g 2H20(g) 2C2(g) rxn* kJ/mol Check & Submit Answer Show Approach There is a second way to use thermodynamic data to calculate ΔGorm . Similar to the standard enth rxn