Answer:
A or C
Explanation:
C- rivers erode the land and stuff with the fast moving currents
A- no idea what that is but if needed to guess it’s a zone for tides tides do something similar to rivers with erosion I’d go with C though sorry if wrong
The element that is the main constituent of paper, diamond, and clothes, among others is CARBON. It forms covalent bonds with itself and other elements. It is one of the most abundant and accessible elements on Earth. All organic compounds consist of at least one Carbon atom.
Answer:
25.6 %.
Explanation:
- To calculate the % of Cl in KClO₄:
<em>% Cl = [Atomic mass of (Cl)/molar mass of KClO₄] x 100</em> = [(35.5 g/mol)/(138.55 g/mol)] x 100 = <em>25.62 % ≅ 25.6 %.</em>
Answer : The correct option is, (A) -x kJ/mol
Explanation :
According to Hess’s law of constant heat summation, the heat absorbed or evolved in a given chemical equation is the same whether the process occurs in one step or several steps.
According to this law, the chemical equation can be treated as ordinary algebraic expression and can be added or subtracted to yield the required equation. That means the enthalpy change of the overall reaction is the sum of the enthalpy changes of the intermediate reactions.
The given chemical reaction is,
Now we have to determine the value of 
for the following reaction i.e,
According to the Hess’s law, if we reverse the reaction then the sign of change.
So, the value 
for the reaction will be:
Hence, the value of for the reaction is -x kJ/mole.
The reaction between the lead iodide, PbI2 and sodium carbonate, Na2CO3, will form the chemical compounds, sodium iodide and lead carbonate as shown below.
PbI2 + Na2CO3 --> NaI + PbCO3
The white precipitate formed in the reaction is PbCO3.
