<h3><u>Answer;</u></h3>
C) A convex lens has a thick center and thin edges; a concave lens has a thin center and thicker edges.
<h3><u>Explanation;</u></h3>
- Convex lens refers to the lens which merges the light rays at a particular point, that travels through it, while a concave lens can be identified as the lens which disperses the light rays around, that hits the lenses.
- A convex lens is thicker at the center, as compared to its edges, while a concave lens is thinner at the center as compared to its edges.
- A concave lens is thicker at the edges than in the middle and spreads light rays apart producing an image smaller than the actual object. A convex lens on the other hand, is thinner at the edges and thicker towards the center, that is they are bent towards a central point.
The atomic mass of the element would simply be equal to
the sum of the weighted average of each isotope, that is:
atomic mass = 59.015 amu * 0.717 + 62.011 amu * (1 – 0.717)
<span>atomic mass = 59.863 amu</span>
For every 1 molecule of Magnesium hydroxide or Mg(OH)2 there will be 2 molecules of HCl neutralized.
If molar mass of magnesium hydroxide is 58.3197g/mol, the amount of mol in 5.50 g magnesium hydroxide should be: 5.50g/ (<span>58.3197g/mol)= 0.0943mol.
Then, the amount of HCl molecule neutralized would be: 2* </span>0.0943mol= 0.18861 mol
If molar mass of HCl is 36.46094 g/mol, the mass of the molecule would be: 0.18861 mol* 36.46094g/mol = 6.88grams
Answer:
46.40 g.
Explanation:
- It is a stichiometric problem.
- The balanced equation of the reaction: 4K + O₂ → 2K₂O.
- It is clear that 4.0 moles of K reacts with 1.0 mole of oxygen produces 2.0 moles of K₂O.
- We should convert the mass of K (38.5 g) into moles using the relation:
<em>n = mass / molar mass,</em>
n = (38.5 g) / (39.098 g/mol) = 0.985 mole.
<em>Using cross multiplication:</em>
4.0 moles of K produces → 2.0 moles of K₂O, from the stichiometry.
0.985 mole of K produces → ??? moles of K₂O.
∴ The number of moles of K₂O produced = (0.985 mole) (2.0 mole) / (4.0 mole) = 0.4925 mole ≅ 0.5 mole.
- Now, we can get the mass of K₂O:
∴ mass = n x molar mass = (0.5 mole) (94.2 g/mol) = 46.40 g.
0.01772288- Calculators do come in handy for this haha
