0.15*240=36 ml of alcohol in <span>240 ml of a 15% alcohol mixture
0.4x = </span>ml of alcohol in x ml of a 40% alcohol mixture
0.2(x+240)= ml of alcohol in (x+240) ml of a 20% alcohol mixture

0.15*240 + 0.4x = 0.2(x+240)
36+0.4x=0.2x+48
0.2x = 12
x=12/0.2=120/6=20 ml of a 40% alcohol mixture

4 0

3 years ago

Express in scientific notation. Make sure your answer has the same number of significant figures as the starting value. (1.8 x 1

slamgirl [31]

Answer : The answer is, $0.2\times 10^{-4}$

Explanation :

Scientific notation : It is defined as the way or representation of expressing the number that are too big or too small that is written in the decimal form. That means always written in the power of 10 form.

For example : 8000 is written as, $8.0\times 10^3$ in this notation, the significant figure is, 1 but $0.8\times 10^4$ in this notation, the significant figures are, 2

The given problem are :

$\frac{1.8\times 10^{-2}}{9\times 10^2}=0.2\times 10^{-4}$

According to the divide and multiplication rules of scientific figures, the final answer is only as precise as the value with the least number of significant figures.

Hence, the answer is, $0.2\times 10^{-4}$

6 0

3 years ago

Read 2 more answers

A compound is found to contain 43.66% of P and 56.33% of O.

jek_recluse [69]

Answer: P2O5 is the empirical formula.

Explanation: When given percentages you can assume that many grams of each atom are in the compound. Then you divide grams by the molar mass of each element, giving you moles. Once you have moles, divide by the smaller molar amount, which should give you 1 mol of Phosphorus and 2.5 mol of Oxygen. Then multiply by 2 in order for both moles to be a whole number. This gets you 2 and 5.

6 0

2 years ago

Special structures in the cells of plants capture sunlight energy to power photosynthesis. What materials must plants obtain fro

Svetach [21]

Answer:

Sunlight

Water

And carbon dioxide

Additional information :

6CO2 + 6H2O → C6H12O6 + 6O2

3 0

3 years ago