A sample of krypton has a volume of 6.00 L, and the pressure is 0.960 atm. If the final temperature is 55.0°C, the final volume

Answer:

78.8%

Explanation:

The equation of the reaction is;

2 Al(s) + Fe2O3(aq) ------> Al2O3(aq) + 2Fe(s)

Number of moles in 20g of Al= 20g/27 g/mol = 0.74 moles

From the reaction equation;

2 moles of Al yields 2 moles of Fe

0.74 moles of Al yields 0.74 moles of Fe

Hence;

Mass of Fe produced = 0.74 moles of Fe * 56 g/mol

Mass of Fe produced = 41.44 g of Fe (This is the theoretical yield of Fe)

percent yield = actual yield/ theoretical yield  * 100

actual yield = 32.67 grams of iron

percent yield = 32.67 g/41.44 g * 100

percent yield = 78.8%

Answer: 6 valence electrons

Explanation: the valence electrons and group are always the same, but when the group numbers are 10 and above, they would be the first number. For example, every element in group 16 has 6 valence electrons.

Answer:

d. oxygen (O2) is the answer

Answer:

d-  334 kJ/g.

Explanation:

You can detect it from the units of the different choices.

a- has the unit J/g.°C that is the unit of the specific heat capacity (c).

b- has the unit Kelvin that is the unit of temperature.

c- has the unit g/mol which is the unit of the molar mass.

d- has the unit kJ/g which is the unit of the enthalpy divided by the no. of rams that is the specific entha;py of fusion.

<em>So, the right choice is: d-  334 kJ/g.</em>