Chemistry Answers

1. Oxygen gas inside a 1200 litres gas tank has a pressure of 1.0 atm. If the temperature remains constant , how much pressure is needed to reduce its volume by one- half (1/2) ?

A 42.1 g piece of metal alloy absorbs 181 J as its temperature increases from 25.0 C to 36.0 C. What is the alloy’s specific heat?

select atoms whose ions have an electron configuration of nd^6(n=3,4,5...).for example , the 2+ ion for V ends the electron configuration with 3d^6

check all that apply;

La

Os

Fe

Rh

Tl

Ti

3 Mn3O4(s)   +   8 Al(s)    →  4 Al2O3(s)   +   9 Mn(s)

How many manganese atoms are released if 54.8 moles of Mn3O4 react with excess aluminum.

A 0.784-g sample of an alloy containing Al and Mg is dissolved and treated to prevent interferences by the alloy’s other constituents. Aluminum and magnesium are precipitated, providing a mixed precipitate of Al(C9H6NO)3 and Mg(C9H6NO)2 that weighs 8.215 g. Igniting the precipitate converts it to a mixture of Al2O3 and MgO that weighs 0.932 g. Calculate the %w/w Al and %w/w Mg in the alloy.

Does butyl cab dissolve sugar

Express the standard reaction enthalpy of the reaction, C₂H₆ (g) + 7/2 0₂ (g) --> 2C0₂ (g) + 3 H₂ 0(1). Given the standard enthalpy for formation of C₂H₆, CO₂and H₂O are -84.6, -393.5 and -285.8 kJ mol^-1 respectively.

The enthalpy of combusbon for methane at 298.15 K is -726.1 kJ mol-1 .What is its enthalpy of

formation? (given: ∆H_f (C0₂ ) =-393.5 kJmol^-1

and ∆H_f (H₂O) = -285.8 kJmol^-1·.

The reaction between solid white phosphorus and oxygen produces solid tetraphosphorusdecoxide (P4O10)

A. Write the balanced chemical equation of the reaction

b. Determine the mass of tetraphosphorusdecoxide (P4O10) formed if 26.0 g of phosphorus (P4) and 49.5 g oxygen (O2) are combined.

C. How much of the excess reactant remains after the reaction stops.

Which of the statements is correct?

1.Carbon may form a polar or non-polar covalent bond.

2.A carbon-hydrogen bond ethane (CH3CH3) is highly polar.

3.In a carbon atom, the 2s and 2p orbitals are equal in energy.

4.Carbon has two valence electrons.