Chemistry help needed urgent answers (1 Viewer)

Blake Henderson

New Member
Joined
Jan 31, 2014
Messages
23
Gender
Male
HSC
2015
A) If an aquarium tank holds 70 litres of water, calculate how much heat energy would be required to heat the tank from 18.2 degrees celcius to 26.5 degrees celcius. Note the density of water is known to be 1g/mL.


B) sucrose is a covalent molecular compound that dissolves in water to produce a solution that does not conduct electricity. Hydrogen chloride is also a covalent molecular compound that dissolves in water to producr a solution that does conduct electricity. Explain why this occurs.


C) with reference to molecular forces, explain why more energy is required to produce hydrogen from water than to produce steam frlm water.


D) you have performed a first-hand investigation of the reactions of a range of metals with dilute acie. Choose a metal which reacts more slowly than magnesium but more rapidly than lead to answer following questions: A) describe youe procedure and the observations you made. B) identify the products of the reaction, by name and formula.


E) potassium has electron configuration of 2,8,8,1 and sulfur has the electron configuration 2,8,6
a) write half equations for each, showing how the ions of each of the elements are formed.
b) identify the product formed when potassium reacts with sulfur to form an ionic compound and write its formula
c) predict the formula for the compound formed between sulfur and oxygen ans identify the bonding present in the compound


F) write balanced equations, showing states, for:
a) phosphorus (s) burns in air to produce a white powder, diphosphorus trioxide
b) dilute sulfuric acid causes insoluble copper carbonate to dissolve, forming copper sulfate and carbon dioxide gas and water.

Need simple and quick answers urgently
 

kevin huynh

New Member
Joined
Feb 2, 2010
Messages
6
Location
Aussie Aussie
Gender
Male
HSC
2014
Question A fairly simple
Answer
- Use the ∆H=mc∆T
=(70 kg×1000g)(4.18)(26.5-18.2)
=2428580J
=2428KJ required
 

kevin huynh

New Member
Joined
Feb 2, 2010
Messages
6
Location
Aussie Aussie
Gender
Male
HSC
2014
For B
- As dissolution occurs, sucrose does not form any free moving ions due to its relatively stable molecule or otherwise known as a non-electrolyte. Whilst HCl is a highly ionizing molecule and when dissolved, form free moving ions of Cl^- and H^+ in the aq solution. Hence, free moving ions acts as moving charges which reflects upon the conductivity HCl in aq form.
 

kevin huynh

New Member
Joined
Feb 2, 2010
Messages
6
Location
Aussie Aussie
Gender
Male
HSC
2014
C
- Causing water to change states from liquid to steam or gaseous, deals with the inter molecular forces or otherwise known as dipole dipole forces. Whilst production of hydrogen of water is carried out by the process of electrolysis, this requires far more energy to break the intra-molecular bonds (H-bonds) than the dipole dipole bonds. Therefore, the process of producing hydrogen requires far greater amounts of energy than producing steam
 

kevin huynh

New Member
Joined
Feb 2, 2010
Messages
6
Location
Aussie Aussie
Gender
Male
HSC
2014
D
- just read a text book on all the pracs and understand the different independent variables. That way you can describe the procedure during the test.
- Answer should be found in text book and just regurgitate
 

Users Who Are Viewing This Thread (Users: 0, Guests: 1)

Top