Which layer of rock contains more humus

The EPA scientist measures the pH level in one area of a river to be lower than normal and writes that a pollutant must have bee

shutvik [7]

Its an example of inference.

4 0

4 years ago

Read 2 more answers

What Period # is this element found in? P

77julia77 [94]

15 is the group that phosphorus is found in.

8 0

3 years ago

When copper metal is added to nitric acid, the following reaction takes place

zlopas [31]

Answer:

The volume of NO₂ gas collected over water at 25.0 °C is 1.68 Liters.

Explanation:

$Cu (s) + 4 HNO_3 (aq) \rightarrow Cu(NO_3)_2 (aq) + 2 H_2O (l) + 2 NO_2 (g)$

Moles of copper = $\frac{2.01 g}{63.55 g/mol}=0.03163 mol$

According to reaction, 1 mol of copper gives 2 moles of nitrogen dioxide gas.

Then 0.03613 moles of copper will give:

$\frac{2}{1}\times 0.03163 mol=0.06326 mol$ of nitrogen dioxide gas

Moles of nitrogen dioxide gas = n = 0.06326 mol

Pressure of the gas = P

P = Total pressure - vapor pressure of water

P = 726 mmHg - 23.8 mmHg = 702.2 mmHg

P = 0.924 atm (1 atm = 760 mmHg)

Temperature of the gas = T = 25.0°C =298.15 K

Volume of the gas = V

$PV=nRT$

$V=\frac{0.06326 mol\times 0.0821 atm L/mol K\times 298.15 K}{0.924 atm}$

V = 1.68 L

The volume of NO₂ gas collected over water at 25.0 °C is 1.68 Liters.

3 0

3 years ago

Convert 78.9 kJ into calories Can you also explain how pls? ty

Naddik [55]

Explanation:

1 kJ = 238.85 cal and

1 cal = 0.004187 kJ

so it will be 78.9×238.85 = 18,844 calories

78.9 Kilojoules (kJ) = 18,844 Calories (IT) (cal)

3 0

3 years ago

how many molecules of sulfuric acid are in a spherical raindrop of diameter 6.0 mm if the acid rain has a concentration of 4.4 *

Vitek1552 [10]

Answer:

The number of moles =

$Moles=4.97\times 10^{-8}$

The number of molecules =

$Molecules = 2.99\times 10^{16}$

Explanation:

Volume of the sphere is given by :

$V=\frac{4}{3}\pi r^{3}$

here, r = radius of the sphere

$radius=\frac{diameter}{2}$

$radius=\frac{6.0}{2}$

Radius = 3 mm

r = 3 mm

1 mm = 0.01 dm (1 millimeter = 0.001 decimeter)

3 mm = 3 x 0.01 dm = 0.03 dm

r = 0.03 dm

("volume must be in dm^3 , this is the reason radius is changed into dm"

"this is done because 1 dm^3 = 1 liter and concentration is always measured in liters")

$V=\frac{4}{3}\pi 0.03^{3}$

$V=\frac{4}{3}\pi 2.7\times 10^{-5}$

$V=1.13\times 10^{-4}dm^{3}$

$V=1.13\times 10^{-4}L$ (1 L = 1 dm3)

Now, concentration "C"=

$C=4.4\times 10^{-4}moles/liter$

The concentration is given by the formula :

$C=\frac{moles}{Volume(L)}$

This is also written as,

$Moles = C\times Volume$

$Moles=1.13\times 10^{-4}\times 4.4\times 10^{-4}$

$Moles=4.97\times 10^{-8}$ moles

One mole of the substance contain "Na"(= Avogadro number of molecules)

So, "n" mole of substance contain =( n x Na )

$N_{a}=6.022\times 10^{23}$

Molecules =

$Molecule=4.97\times 10^{-8}\times 6.022\times 10^{23}$

$Molecules = 2.99\times 10^{16}$ molecules

7 0

3 years ago