6th grade science help me please (:

Ocean water contains 3.5% NaCl by mass. How many grams of sodium chloride can be obtained from 750 g of seawater

Masteriza [31]

26.25g

Explanation:

Given parameters:

Percentage of NaCl in ocean water = 3.5%

Mass of given seawater = 750g

Unknown:

Mass of NaCl in the seawater = ?

Solution:

This is a simple percentage problem:

We have been given that ocean water contains 3.5% of NaCl;

Therefore;

Mass of NaCl in seawater = Percentage of NaCl in ocean water x Mass of seawater

Mass of NaCl in seawater = $\frac{3.5}{100}$ x 750g = 26.25g

Learn more:

Percentage brainly.com/question/2917248

#learnwithBrainly

3 0

3 years ago

Translate the world equation in skeleton equation and balance them

alexdok [17]

Answer:

The balanced equation is: H2 (g) +Cl2 (g) →2HCl (g)

Explanation:

Balancing chemical equation refers to balancing the stoichiometric coefficients on the reactants and products side. This must be done as the chemical equation obeys the law of conservation of mass and momentum.

The representation of a chemical reaction in the form of substances is known as a chemical equation. The equation in which the number of atoms of all the molecules is equal on both sides of the equation is known as a balanced chemical equation. The Law of conservation of mass governs the balancing of a chemical equation.

Given chemical equation

The balanced chemical equation for the hydrogen + chlorine -> Hydrogen Chloride.

H2 + Cl2 → 2HCl

The equation is balanced as on the reactants side there are two hydrogens present and the same on the products side. For chlorine as well the same thing goes two chlorine atoms on the reactants side and two on the products side.

4 0

3 years ago

Microwave ovens heat food by creating microwave electromagnetic radiation that is absorbed by water molecules in the food.

Nikolay [14]

Explanation:

It is known that relation between heat energy and temperature change is as follows.

Q = $mC \Delta T$

where, q = heat energy

m = mass of the solution or solvent

$\Delta T$ = change in temperature

Hence, putting the given values into the above formula as follows.

Q = $mC \Delta T$

= $110.0 g \times \frac{315 J}{75^{o}C} \times (100 - 25)^{o}C$

= 34650 J

Now, calculate the energy of photons at wavelength 3.02 mm as follows.

E = $\frac{hc}{\lambda}$

where, h = planks constant = $6.626 \times 10^{-34} Js$

c = velocity of light = $3 \times 10^{8}$ m/s

$\lambda$ = wavelength = 3.02 mm = $3.02 \times 10^{-3}$ m (as 1 m = 1000 mm)

Therefore, putting the given values into the above formula as follows.

E = $\frac{hc}{\lambda}$

= $\frac{6.626 \times 10^{-34} Js \times 3 \times 10^{8} m/s}{3.02 \times 10^{-3} m}$

= $6.58 \times 10^{-23}$ J

Now, the number of photons required of energy $6.58 \times 10^{-23}$ J/photon for the total energy of 34650 J as follows.

$E_{total} = n \times E$

n = $\frac{E_{total}}{E}$

= $\frac{34650 J}{6.58 \times 10^{-23}}$

= $5265.95 \times 10^{23}$ photons

or, = $5.265 \times 10^{26}$ photons

Thus, we can conclude that the minimum number of photons present are $5.265 \times 10^{26}$ .

7 0

3 years ago

PLEASE help

Goryan [66]

Answer:

b

Explanation:

because it has gained an electron

4 0

3 years ago

When 1 mol each of C2H5OH and CH3CO2H are allowed to react in 1 L of the solvent dioxane, equilibrium is established when 13 mol

taurus [48]

Answer:

Keq = 4

Explanation:

The correct statement is:

When 1 mol each of C₂H₅OH and CH₃CO₂H are allowed to react in 1 L of the solvent dioxane, equilibrium is established when 1/3 mol of each of the reactants remains. Calculate the equilibrium constant for the reaction. (Note: Water is a solute in this reaction.)

1. Equilibrium equation

C₂H₅OH + CH₃CO₂H ⇄ CH₃CO₂C₂H₅ + H₂O

↑ ↑ ↑ ↑

ethanol acetic acid ethyl acetate water

2. Equilibrium constant

Keq = [Products] / [Reactants], each raised to tis stoichiometrical coefficient.

Since water is also a solute in this reaction (the solvent is dioxane) its concentration will appear in the equilibrium constant.

$Keq=\frac{[CH_3CO_2C_2H_5]\cdot [H_2O]}{[C_2H_5OH]\cdot [CH_3CO_2H]}$

3. Equlibrium concentrations:

Moles

C₂H₅OH + CH₃CO₂H ⇄ CH₃CO₂C₂H₅ + H₂O

Initial 1 1 0 0

Change -2/3 -2/3 +2/3 +2/3

End 1/3 1/3 2/3 2/3

Since the volume is 1 liter, the concentration is equal to the number of moles

4. Calculations:

$Keq=\frac{[CH_3CO_2C_2H_5]\cdot [H_2O]}{[C_2H_5OH]\cdot [CH_3CO_2H]}=\frac{2/3\cdot 2/3}{1/3\cdot 1/3}=4$

4 0

3 years ago