Answer:
A. your observations in writing
Explanation:
Descriptive investigation is one of the mode of inquiries in science. It is devoid of the usual collection of data in the field or setting up laboratory experiments to compared variables.
- In descriptive investigation, observations are usually done in writing.
- They are usually common in Astrology.
- Such investigation involves a question without a hypothesis ensuing.
- Tests are usually not carried out in descriptive investigation.
Answer:
In liquid water, hydrogen bonds are constantly being formed and broken as the water molecules slide past each other.
Explanation:
The breaking of these bonds is caused by the energy of motion (kinetic energy) of the water molecules due to the heat contained in the system.
(hope that helps) :)
Answer:
1. (NH₄)₂S(s) -----> NH₄+(aq) + S²-(aq)
2. Al³+ (aq) + PO₄³+ (aq) ----> AlPO₄ (s)
Explanation:
The dissociation of ammonium sulphide, (NH₄)₂S when dissolved in water is given in the equation below:
(NH₄)₂S(s) -----> NH₄+(aq) + S²-(aq)
However very little S²- ions are present in solution due to the very basic nature of the S²- ion (Kb = 1 x 105).
The ammonium ion being a better proton donor than water, donates a proton to sulphide ion to form hydrosulphide ion which exists in equilibrium with aqueous ammonia.
S²- (aq) + NH₄+ (aq) ⇌ SH- (aq) + NH₃ (aq)
Aqueous solutions of ammonium sulfide are smelly due to the release of hydrogen sulfide and ammonia, hence, their use in making stink bombs.
2. The reaction between aluminium nitrate and sodium phosphatein aqueous solution is a double decomposition reaction whish results in the precipitation of insoluble aluminium phosphate. The equation of the reaction is given below :
Al(NO₃)₃ (aq) + Na₃PO₄ (aq) ----> AlPO₄ (s) + 3 NaNO₃ (aq)
The net ionic equation is given below:
Al³+ (aq) + PO₄³+ (aq) ----> AlPO₄ (s)
Answer:
C. AlCl3 is a covalent compound.
Explanation:
It is formed by mutual sharing of electrons between two atoms each contributing equal number of electrons to the electron pair.
