A 1.000 g sample of copper reacts with an unknown element X to form 1.908 g...

A 1.000 g sample of copper reacts with an unknown element X to form 1.908 g Cu5X9. What is element X??

Expert Solution

no of moles of Cu = W/G.A.Wt

= 1/63.546 = 0.015736 moles

5Cu(s) + 9X-------------> Cu5X9

5 moles of Cu react with excess of X to gives 1 mole of Cu5X9

0.015736moles of Cu react with excess of X to gives = 1*0.015736/5 = 0.0031472moles fo Cu5X9

molar mass of Cu5X9 = mass of Cu5X9/no of moles

= 1.908/0.0031472 = 606.25g/mole

9 atoms molar mass of X = molar mass of Cu5X9- atomic mass of Cu

= 606.25-5*63.546

= 288.52

atomic mass of X = 288.52/9 = 32.06g/mole

The unknown element X is sulfur

sulfur >>>>answer

queen_honey_blossom answered 7 months ago

A sample of 10.00 g of sodium reacts with oxygen to form 15.02 g of sodium...

A sample of 10.00 g of sodium reacts with oxygen to form 15.02 g of sodium oxide (Na2O) and sodium peroxide (Na2O2). Calculate the percent composition of the mixture. ___% Na2O ___% Na2O2

A 52 g sample of iron reacts with 22 g of oxygen to form how many...

A 52 g sample of iron reacts with 22 g of oxygen to form how many grams of iron oxide? Express your answer using two significant figures.

element E is a main group element and reacts with oxygen to form the ionic compound...

element E is a main group element and reacts with oxygen to form the ionic compound E2O. An atom of E is larger than an atom of calcium and in a similar reaction an atom of E is less reactive than an atom of Rb

A 215 g block of copper at 505.0°C is plunged into 1.000 kg of water (T...

A 215 g block of copper at 505.0°C is plunged into 1.000 kg of water (T = 23.4 °C) in an insulated container. What will be the final equilibrium T in °C of the water and the Cu? (sCu = 0.385 J g-1 °C-1)

A 1.000 g-sample of a compound undergoes combustion in a bomb calorimeter. The temperature of the...

A 1.000 g-sample of a compound undergoes combustion in a bomb calorimeter. The temperature of the calorimeter rises from 12.0 oC to 70.8 oC. If the heat capacity of the calorimeter is 810.1 J/oC, determine the change in internal energy for the combustion reaction, ΔΔ ΔΔErxn, in kJ/mol. The molar mass of the compound is 142.32 g/mol. What is the energy change associated with 3.5 mol of D being formed? 2 B + C ⟶⟶ ⟶⟶ D + E ...

An 65.73 g sample of aluminum is placed on a 56.35 g sample of copper initially...

An 65.73 g sample of aluminum is placed on a 56.35 g sample of copper initially at 111.86oC. If the heat is only transferred between the metals (with no loss to the surroundings) and the final temperature of both metals is 36.38oC, what is the inital temperature (in oC) of aluminum?

.Calculate the number of copper atoms in a 63.55 g sample of copper. .What is the...

.Calculate the number of copper atoms in a 63.55 g sample of copper. .What is the mass in grams of 0.509 moles of AlCl3? .Which of the following 100.0 g samples contains the greatest number of atoms? a. Magnesium b. Zinc c. Silver

A steel sample weighing 1.000 g is dissolved in acids and treated with persulfate and periodate...

A steel sample weighing 1.000 g is dissolved in acids and treated with persulfate and periodate to oxidize Mn to MnO4- and Cr to Cr2O7-. The solution is finally diluted to 100.00 mL in a volumetric flask. An aliquot placed in a 1.00-cm cuvette yielded an absorbance of 0.113 at 440 nm and of 1.304 at 545 nm. The absorbance for a reagent blank was 0.005 at 440 nm and 0.008 at 545 nm. Calculate the percentages (m/m) of Cr...

What it means the degree of g(x) is 0? (g(x) is a non zero element of...

What it means the degree of g(x) is 0? (g(x) is a non zero element of N of minimal degree. Where N is an ideal in F[x]. ) the geometrical meaning of degree of polynomial is 0?

1. When H2(g) reacts with O2(g) to form H2O(g) , 242 kJ of energy are evolved...

1. When H2(g) reacts with O2(g) to form H2O(g) , 242 kJ of energy are evolved for each mole of H2(g) that reacts. Write a balanced thermochemical equation for the reaction with an energy term in kJ as part of the equation. Note that the answer box for the energy term is case sensitive. Use the SMALLEST INTEGER coefficients possible and put the energy term (including the units) in the last box on the appropriate side of the equation. If...

Question