Answer:
Explanation:
mass of 1mole of brick = mass of 1 brick x avagadro number
= 4 kg x 6.022 x 10^23 bricks = 2.4 x 10^24 kg
No. of moles of bricks have a mass equal to the mass of the earth
= mass of earth / mass of 1 mole of brick
= [ 6 x 10^27 ] / [ 2.4 x 10^24 ]
= 2.5 x 10^3
= 2500 moles
A food web is a system of interlocking and interdependent food chains.
A food chain is a hierarchical series of organisms each dependent on the next as a source of food.
Basically, the difference of the two is that a food web contains multiple different species in the same level that eat the animal below it's status. A food chain is one after the other.
HI.3H2O. This is the answer
Molar mass H₂O = 18.0 g/mol
number of moles :
1.0 / 18.0 => 0.055 moles
1 mole -------------- 6.02 x 10²³ molecules
0.055 moles -------- ? molecules
molecules = 0.055 x ( 6.02 x 10²³) / 1
molecules = 3.311x10²² / 1
= 3.311 x 10²² molecules
hope this helps!
Explanation:
a. Magnesium oxide is used mainly in soil treatment and groundwater remediation, wastewater treatment, etc. it is used for it's acid buffering capacity and effectiveness in dissolving heavy metals.
b. MgO is the chemical equation for the reaction.
c. multiply the given mass of O2 by the inverse of it's molar mass. multiply the molar ratio (from the balanced equation) between O2 and MgO. Multiply by the molar mass of MgO. 32g O2 x 1 mol O2 ... 32g O2 x 2mol MgO 1mol O2 x 40g MgO. .... 1mol MgO = 80 g.
d. Mg (s) + 2 HCl (aq) produces MgCl 2(aq) + H 2 (g). Where the letter "s" stands for solids, and "g" is for gas and "aq" represents aqueous solution.