In this question, XB3(aq) is an ionic compound which will have the releasing of 3 B⁻ ions ions in water for every molecule of XB3 that dissolves.
XB3(s) --> X+(aq) + 3 B⁻(aq)
[B⁻] = 0.22 mol XB3/1L × 3 mol B⁻ / 1 mol XB3 = 0.66 M
The answer to this question is [B⁻] = 0.66 M
Here are the steps for finding an emprical formula.
To begin, we need to change the grams to a percentage. We can simply take the number and call it our percentage. (i.e 0.262%)
Then, we have a simply stoichiometry step. We put our starting number over 1, as usual. The next "Step" is putting in the molar mass of that particular element on the bottom, with one on top. It should look like this:
0.262% N 1
-------------- x ----------------
1 14.007g N
We would then divide those two numbers to get our answer. Repeat for the other elements included, until we have all of them done.
After that, we need to find the smallest number that was the answer to one of the equations. For example, if the product of Hydrogen was the smallest formed, we would locate that number. We then divide ALL of our answers by that smallest number.
Remember, whenever doing empirical formulas, significant figures matter.
Once we have our smallest numbers, we need to round our numbers to the nearest whole number. HOWEVER, to do this we need to multiply all of the numbers by the SAME whole number.
For example, if one of our numbers was 1.33, we would multiply by 3 to get a whole number. However, we would also need to multiply the rest of our products by the same number. If we do not get close to whole numbers (you can round), we need to try with multiplying a different number.
Then, we need to take those whole numbers we got for each number, and plug in to make a compound. For example, if our products were 6 for nitrogen, 3 for hydrogen, and 2 for chlorine, our final empirical formula would be N6H3Cl2.
Hope I could help! If it was a bit wordy please let me know and I'd be more than willing to clarify.
Answer:
B. 4 ham slices
Explanation:
A chemical reaction involves one or more substances known as reactants combining chemically to give one or more substances known as products.
Reactants in chemical reactions combine in definite mole or mass ratios to give products. Therefore, when one substance is present in excess of what is required to combine with another to form products, that substance is known as the excess reagent. The other substance which is present in a smaller amount and which when used up, the reaction stops is known as the limiting reagent.
From the illustration of the sandwiches in the question, the recipe for one sandwich represents the chemical equation of a reaction. The equation form is given below:
2 cheese slices + 1 ham slice + 2 bread slices ---> 1 sandwich
The ratio of the reactant is 2 : 1 : 2
From the available ingredients, 12 cheese slices, 10 ham slices, 12 bread slices.
12 cheese slices will require 6 ham slices and 12 bread slices to produce 6 sandwiches.
However, since there are 10 ham slices, 4 ham slices will be left over unused. This is the excess or leftover reactant.
Solids-
cooked spinach, salmon, or artichokes.
liquids-
urine or milk.
Use the D = M/V equation, in which Density can be found by dividing <em>Mass/Volume</em>.
To solve, first find a rectangular prism tub that is filled to a certain level. Next, place the rock inside to find the amount of displacement (or how high the water level goes up.) In this way, you can find the <em>volume of the rock</em>.
Next, solve for the Mass. This can be found by dividing the total weight from the gravitational pull. This would give you the mass.
Finally, to find Density, divide the Mass found with the Volume. This would give you your final answer
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