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2 years ago

Heyyyyyyy......................

Chemistry

2 answers:

Maksim231197 [3]2 years ago

6 0

Answer:

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Explanation:

natita [175]2 years ago

4 0

Answer:

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What is Molecular mass?

MArishka [77]

Answer:

Molecular mass is the amount of mass associated with a molecule. It is also called as molecular weight. It can be calculated by adding the mass of each atom multiplied by the number of atoms of the element present in the molecule. For example, water is made up of 2 hydrogen atoms and 1 oxygen atom.

Explanation:

7 0

2 years ago

Read 2 more answers

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

2 years ago

A sample of black coffee was measured to have [h3o+] = 7.94 × 10−6. what is true about this solution?

Sveta_85 [38]

Being given the hydronium (or simply the hydrogen) ion concentration (molarity), one of the easiest properties of the solution to determine is its pH. The pH of a solution indicates the acidity (or basicity) of a given solution. The typical pH range of solutions is from 1 to 14, with 7 being neutral, 1 to 6 being acidic, and 8 to 14 being basic.

To determine the pH of a solution, the negative log (-log) of the hydronium/hydrogen ion concentration (molarity) of the solution is calculated. Thus (assuming that the given hydrogen ion concentration is in molarity (mol/L)),

pH = -log( $H^{+}$ ) or -log( $H_{3} O^{+}$
pH = -log (7.94 × 10−6 mol/L)
pH = 5.13

Because the pH is less than 7 (within the range 1 to 6), then the black coffee solution is acidic.

6 0

3 years ago

Need help with question please .. -20 points

san4es73 [151]

Answer:

B oklolol

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8 0

2 years ago

Calculate the change internal energy (ΔE) for a system that is giving off 65.0 kJ of heat and is performing 855 J of work on the

ollegr [7]

Answer: -64.1 kJ.

Explanation:

According to first law of thermodynamics:

$\Delta E=q+w$

$\Delta E$ =Change in internal energy

q = heat absorbed or released

w = work done or by the system

w = work done by the system= $-P\Delta V$ {Work is done by the system is negative as the final volume is greater than initial volume}

w = -855 Joules = 0.855 kJ (1kJ=1000J)

q = -65.0 kJ {Heat released by the system is negative}

$\Delta E=-65.0J-(-0.855J)=-64.1kJ$

Thus the change internal energy (ΔE) for a system that is giving off 65.0 kJ of heat and is performing 855 J of work on the surroundings is -64.1 kJ.

6 0

3 years ago