Answer:
54 g
Explanation:
Given data:
Mass of carbon = 18 g
Mass of CO₂ = 72 g
Mass of oxygen needed = ?
Solution:
Chemical reaction:
C + O₂ → CO₂
according to law of conservation mass, mass can neither be created nor destroyed in a chemical equation.
This law was given by French chemist Antoine Lavoisier in 1789. According to this law mass of reactant and mass of product must be equal, because masses are not created or destroyed in a chemical reaction.
In given photosynthesis reaction:
6CO₂ + 6H₂O + energy → C₆H₁₂O₆ + 6O₂
there are six carbon atoms, eighteen oxygen atoms and twelve hydrogen atoms on the both side of equation so this reaction followed the law of conservation of mass.
In a similar way,
C + O₂ → CO₂
18 g + X = 72
X = 72 -18
X = 54 g
Thus, 54 g of O₂ are required.
One atom of carbon weighs exactly 12/6.022x10^23 = 1.9927x10^-23 grams<span>.</span>
Answer:
c) a compound
Explanation:
a compound is something made up of two or more separate elements, the separate elements in water are hydrogen(H) and oxygen(O)
Calcium forms an ion with a positive 2 charge and chlorine forms an ion with a negative one charg, so the formula is <span>CaC<span>l2</span></span>
Group 1 metals and group 2 metals form positive ions by losing 1 and 2 electrons respectively. Non-metals in group 17 gain 1, group 16 gain 2 and group 15 gain 3. Elements which lose electrons form positive ions while elements that gain electrons form negative ions.
To write a formula, you must balance charges so the overall charge is zero. A simple way to do this is to swap the # of the ion's charge and make it the subscript of the other ion. However, leave off the number 1 and reduce to lowest whole number ratio.
