Answer:
A.
Explanation:
Water was added to the reaction after the completion of the reaction so as to lower the solubility if the product in the solution therefore, the product can be precipitated out. On adding water the reaction moves in forward direction and more product is formed. (By Le Chatelier's principle). Thus, the precipitation occurs. Hence, option A is correct.
Answer:
There are 9.8 ×1021. formula units in 10,005.8gCaO
moles of CO gas : 1.545
<h3>Further explanation</h3>
Standard conditions for temperature and pressure are used as a reference in certain calculations or conditions
There are 2 conditions that are usually used as a reference : STP and RTP
Assuming the STP state :
Conditions at T 0 ° C and P 1 atm are stated by STP (Standard Temperature and Pressure). At STP, Vm is 22.4 liters / mol.
Then for 34.6 L of CO gas :

64: C
65: D because weathering is defined as rock being eroded/changed
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