Due to hydrogen bonding there is a formation of cage like structure called lattice in ice due to which <span> density of ice is less than that of water. Moreover, it is a known fact that density of water is maximum at 4°C.</span>
Answer: The ion that contribute to water hardness are:
--> a. Ca2+
--> b. (HCO)3^- and
--> c. Mg2+
While K+ DOES NOT contribute to water hardness.
Explanation:
WATER in chemistry is known as a universal solvent. This is so because it is polar in nature and dissolves most inorganic solutes and some polar organic solutes to form aqueous solutions. It is composed of elements such as hydrogen and oxygen in the combined ratio of 2:1.
Water is said to be HARD if it does not lather readily with soap. There are two types of water hardness:
--> Permanent hardness: This is mainly due to the presence of CALCIUM and MAGNESIUM ions in the form of soluble tetraoxosulphate(VI) and chlorides. These ions are removed by adding washing soda or caustic soda.
--> Temporary hardness: This is due to the presence of calcium HYDROGENTRIOXOCARBONATES. It can be removed by boiling and using slaked lime.
Therefore from the above given ions, Ca2+,(HCO)3^- and Mg2+ contributes to water hardness.
Answer:
the anserw should be 665KJ
Flame (fire) is the effect of a chemical reaction that produces visible light and heat. The chemical reaction is going on in the substance being burned.. Thats why coals glow and flames seem to leap into the air.
<span>If your reaction does not have a flame, then either it is not producing visible light or the reaction does not occur in the air above the substance.</span>
Answer:
Rocks are the aggregate of minerals. There are three distinct categories of rocks, namely the sedimentary, metamorphic and the igneous rocks.
- The sedimentary rocks are formed from the deposition, compaction, and lithification of soft sediments that are transported from one place to another by the agents such as wind, water, and ice. For example, Sandstone and Shale.
- The metamorphic rocks are derived from the previously existing sedimentary, igneous or other metamorphic rocks, due to the influence of extremely high pressure as well as temperature conditions. For example, Quartzite and Marble.
- The igneous rocks are those rocks that are formed from the cooling and crystallization of magma. For example, Granite and Diorite.
All these three types of rocks are formed by different processes and their mode of origins are also different.
