PLEASE HELP!!!!!!!!!!!!!!!!!!!! ASAP!!!!!!!!! Which two elements are mainly found in the inner and outer core?

One mole of X contains how many molecules of X

mixer [17]

Answer:

The mole is represented by Avogadro's number, which is 6.022×1023 atoms or molecules per mol

Explanation:

5 0

3 years ago

Determine the empirical formulas for compounds with the following percent compositions:

White raven [17]

Answer: a) $CS_2$

b) $CH_2O$

Explanation:

a) If percentage are given then we are taking total mass is 100 grams.

So, the mass of each element is equal to the percentage given.

Mass of C = 15.8g

Mass of S= 84.2 g

Step 1 : convert given masses into moles.

Moles of C = $\frac{\text{ given mass of C}}{\text{ molar mass of C}}= \frac{15.8g}{12g/mole}=1.32moles$

Moles of S= $\frac{\text{ given mass of S}}{\text{ molar mass of S}}= \frac{84.2g}{32g/mole}=2.63moles$

Step 2 : For the mole ratio, divide each value of moles by the smallest number of moles calculated.

For C = $\frac{1.32}{1.32}=1$

For S = $\frac{2.63}{1.32}=2$

The ratio of C : S = 1:2

Hence the empirical formula is $CS_2$

b) Mass of C= 40 g

Mass of H= 6.7 g

Mass of O = 53.3 g

Step 1 : convert given masses into moles.

Moles of C = $\frac{\text{ given mass of C}}{\text{ molar mass of C}}= \frac{40g}{12g/mole}=3.33moles$

Moles of H = $\frac{\text{ given mass of H}}{\text{ molar mass of H}}= \frac{6.7g}{1g/mole}=6.7moles$

Moles of O = $\frac{\text{ given mass of O}}{\text{ molar mass of O}}= \frac{53.3g}{16g/mole}=3.33moles$

Step 2 : For the mole ratio, divide each value of moles by the smallest number of moles calculated.

For C = $\frac{3.33}{3.33}=1$

For H = $\frac{6.7}{3.33}=2$

For O = $\frac{3.33}{3.33}=1$

The ratio of C : H: O= 1 :2: 1

Hence the empirical formula is $CH_2O$

5 0

3 years ago

Why is water considered the greatest solvent on earth

kotykmax [81]

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

6 0

4 years ago

Suppose you have an aqueous solution containing 158.2 g KOHper

postnew [5]

Answer:

1132.8 ml of water

Explanation:

you have an aqueous solution contains 158.2 g KOH per liter

so concentration =158.2/56 = 2.825M

Molarity =2.825

that means you have 2.825 moles of KOH in 1.00L solution

Mass of Soluet(KOH)= 152.8g

Volume of solution= 1.00L

density of solution= 1.13g/cm3 =1.13g/ml

therefore mass of solution = VolumeX density = 1000mL X 1.13g/ml.=1130g

Mass of solvent(water)= mass of solution- mass of solute(KOH)=1130-152.8= 997.2g

Molality= moles of solute/mass of solvent(Kg)

=2.825/(997.2/1000)= 2.832molal

to prepare a 0.250 molal solution of KOH, starting with 100.0ml ofthe orginal solution

0.250*X =2.832 *100

X = 1132.8 ml of water you have to add

4 0

3 years ago

Which of the following best defines climate)_( Short-term atmospheric conditions of a region Ob The weather pattern of an area o

Marina86 [1]

Answer:

Average weather conditions of a region over the long term

Explanation:

Climate is the long-term average of weather, typically averaged over a period of 30 years. More rigorously, it denotes the mean and variability of meteorological variables over a time spanning from months to millions of years.

4 0

3 years ago