Answer:
d = 3.65 g/mL
Explanation:
This problem is solved by using the equation:
d= m/V
But we have to be careful with the number of significant figures and number of decimals to report our result.
There are two steps to calculate the density:
1. We should perform a substraction to determine the mass of potassium chloride.
mass KCl =( Weight cylinder + KCl ) - (Weight empty cylinder)
92.7 g - 5.55 g = 87.15 g = 87.2 ( rounded to 1 decimal place)
The rule for addition and substraction is that we round the result to the number of decimal place with the least number of decimals ( 92.7 has one decimal, 5.55 has two)
2. We can now calculate the density by dividing the mass into the volume, but retaining the number of significant figures to the number with the smallest number of significant figures, the rule for multiplication and division.
d= m/V = 87.2 g / 23.9 mL = 3.648 g/mL
87.2 has three significant figures and so does 23.9, so we have to round to 3 significant figures.
The rule here is that if the left most digital to be dropped is greater o equal to 5, we round to the nearest higher digit, so 8 is greater than 5 and we rounded up 3.648 to 3.65.
Answer:
There are 70 grams of KOH
Explanation:
First, we calculate the weight of 1 mol of KOH:
Weight 1 mol KOH: Weight K + Weight 0 + Weight H= 39g+ 1g+ 16g= 56 g/mol
1 mol-------56 g KOH
1,25 mol----x= (1,25 molx56 g KOH)/1 mol= <em>70 g KOH</em>
Answer:
I have for Decompostion
Explanation:
A decomposition reaction occurs when one reactant breaks down into two or more products. It can be represented by the general equation: AB → A + B. In this equation, AB represents the reactant that begins the reaction, and A and B represent the products of the reaction
0.04350179862
Explanation:
Make sure to check for sig figs though. Basically, you have 2.54 mL and you multiply that by the 0.789 g/mL and mL cancels out and you are left with 2.00406g. There are 46.06844 grams per mol of ethanol, so to cancel out grams we multiply by 1/46.06844. And then we are left with 0.04350179862 mol
Answer:
A
Explanation:
Thats the only one that makes sense.
