Answer:
CeO₂
Explanation:
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In this case, since we are given the mass of both cerium and the cerium oxide, we can first compute the moles of cerium and the moles of oxygen as shown below:


Now, we simply divide each moles by 0.03 as the fewest moles in the formula to obtain the simplest formula (empirical formula) of this oxide:

Thus, the formula turns out:

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Answer:
6.02 x 10²³ atoms
Explanation:
Given parameters:
Number of moles CaSO₄ = 1 mole
Unknown:
Number of Ca atoms in the given compound = ?
Solution:
The given compound is:
CaSO₄
1 mole of CaSO₄ is made up of 1 mole of Ca atoms
Now;
1 mole of any substance contains 6.02 x 10²³ atoms
1 mole of Ca atoms will also contain 6.02 x 10²³ atoms
We may apply a mass balance here. The total moles of NaCl will remain constant before and after the mixing of the solutions. We have three solutions:
1) 25 ml of 5 M NaCl
2) 100 ml of 0 M NaCl
3) A mixture of these solutions with volume 125 ml and concentration C
The moles of a substance are equal to the product of the concentration and volume. Thus:
25 * 5 + 100 * 0 = 125 * C
C = 1 M
The concentration of the final solution is 1 M.
1) H2O is able to dissolve both polar molecules and non polar ones
2) due to its extreme polarity it can even dissolve some I onic compounds
3 the h2o molecule itself is small in size