How many moles are in 64 grams of Ca(NO3
)2

Answer:

Molarity of a solution = 0.3 mol/liter

Explanation:

Given:

Moles of solute = 15 moles

Amount of solution = 50 liters

Find:

Molarity of a solution

Computation:

Molarity of a solution = Moles of solute / Amount of solution

Molarity of a solution = 15 / 50

Molarity of a solution = 0.3 mol/liter

Answer:

9.52 × 10³ J

Explanation:

There is some info missing but I found it on the web.

Calculate the energy required to heat 179g of ethanol from -2.2 °C to 19.6 °C. Assume the specific heat capacity of ethanol under these conditions is 2.44 J/g.°C. Be sure your answer has the correct number of significant digits.

Step 1: Given data

Step 2: Calculate the temperature change

ΔT = 19.6 °C - (-2.2 °C) = 21.8 °C

Step 3: Calculate the energy required (Q)

We will use the following expression.

Q = c × m × ΔT

Q = 2.44 J/g.°C × 179 g × 21.8 °C

Q = 9.52 × 10³ J

Answer:

it's the 2 I'm pretty sure

Explanation:

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Answer:

Explanation:

sd dsf sd f sdf sdf

Answer:

The molar mass of carbon

Explanation:

Before the mass (in grams) of two moles of carbon can be determined, the molar mass of the element would be needed.

This is because the number of mole of an element is the ratio of its mass and the molar mass. That is,

number of mole = mass/molar mass

Hence, the mass of elements can be obtained by making it the subject of the formular;

mass = number of mole x molar mass

Therefore, the molar mass of carbon would be needed before the mass of 2 moles of the element can be determined.

Answer:

false.nowadays humans are destroying forest,extracted more minerals,making pollution. in my view.

Answer:

Hey..! I know only 1st one answer

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Answer:

The temperature of the mixture is 60°C

Explanation:

We can write the energy of water as follows:

E = m×C×T

Where E is energy in Joules, m is mass of water, C is specific heat of water = 4.184J/g°C and T is temperature

Replacing fot both samples:

E = 20g×4.184J/g°C×30°C

E = 2510.4J

E = 40g×4.184J/g°C×75°C

E = 12552J

The total energy of the mixture is 12552J + 2510.4J = 15062.4J

Mass = 60g:

15062.4J = 60g×4.184J/g°C×T

60°C = T

Answer:

See attached picture.

Explanation:

Hello!

In this case, since C2H3Cl is an organic compound we need a central C-C parent chain to which the three hydrogen atoms and one chlorine atom provides the electrons to get all the octets except for H as given on the statement.

In such a way, on the attached picture you can find the required Lewis dot structure without formal charges and with all the unshared electron pairs, considering there is a double bond binding the central carbon atoms in order to compete their octets.

Best regards!

The lewis structure of given molecule is given below. Carbon has 4 electron. out of which electron make bond with carbon and one with hydrogen and chlorine.

If the compound's molecular formula is known, electron dot structures or Lewis dot formulas can be drawn. It describes the type of bond and the placement of the atoms within the molecule that are joined together. In homage of American chemist Gilbert Newton Lewis, molecules are depicted as having a Lewis electron dot structure or simply a Lewis structure. The lewis structure of given molecule is given below.

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Answer:

it takes two hydrogen atoms for every oxygen atom to produce this reaction, so the mole ratio between hydrogen and oxygen is 2:1

Answer:

Zero with the subscripts, +2 without them.

Explanation:

Hello!

In this case, since we consider that two silicon are bonded with four oxygen atoms to form silicon oxide according to the following chemical equation:

[tex]Si^{4+}+O^{2-}\rightarrow Si_2O_4[/tex]

It is also possible to realize it can be simplified to obtain:

[tex]SiO_2[/tex]

Which means that the total charge with the subscripts is zero, and without the subscripts +2 (+4-2).

Best regards!

Answer:

- the central atom is usually the atom with the lowest subscript in the molecular formula and the atom that can form the most bonds. If all of the atoms usually form the same number of bonds, the least electronegative atom is usually the central atom.

- molecular shape (the shape that a single molecule has) is important in determining how the molecule interacts and reacts with other molecules. Molecular shape also influences the boiling point and melting point of molecules. If all molecules were linear then life as we know it would not exist.

Answer:

Collision theory states that the rate of a chemical reaction is proportional to the number of collisions between reactant molecules. The more often reactant molecules collide, the more often they react with one another, and the faster the reaction rate.

Answer:

[tex]1.214\ g[/tex]

Explanation:

[tex]We\ know\ that,\\No.\ of\ molecules\ of\ Hydrobromic\ acid=9.03*10^{21} HBr\ molecules\\Now,\\We\ know\ that\ Hydrobromic\ acid\ is\ constituted\ by\ 1\ Hydrogen\ molecule\\ and\ 1\ Bromine\ molecule.\\Gram\ Atomic\ Mass\ of\ Bromine \approx 80\ g\\Gram\ Atomic\ Mass\ of\ Hydrogen =1\ g\\Hence,\\The\ Gram\ Molecular\ Mass\ Of\ Hydrobromic\ Acid=1*1+1*80=81\ g\\Avagadro's\ Constant=6.022*10^{23}\ particles[/tex]

[tex]Now,\\We\ know\ that,\\Mass=\frac{No.\ of\ particles}{Avagadro's\ Constant}*GMM\\Here,\\Mass\ of\ 9.03*10^{21} molecules\ of\ HBr= \frac{9.03*10^{21}}{6.022*10^{23}}*81 \approx 1.214\ g[/tex]

Answer:

More slowly than

Larger than

Weaker

Explanation:

The vapor pressure of a solution describes how quickly a solution will turn into vapour. If we say that a solution has a high vapour pressure, we are actually saying that the solution turns into vapour more quickly.

Acetone has a higher vapour pressure than water so acetone turns to vapour quicker than water.

Vapour pressure has a lot to do with the magnitude of intermolecular forces in solution. The stronger the magnitude of intermolecular forces, the lower the vapor pressure and the more slowly the solution evapourates.

So, the hydrogen bonds in water provides stronger intermolecular forces than dispersion and dipole interaction in acetone. Hence, water vaporizes more slowly than acetone.

Answer:

the five major branches of chemistry are organic, inorganic, analytical, physical, and biochemistry.

This question is not complete, the complete question is;

Calculate the final pH of a solution made by the addition of 10 mL of a 0.5 M NaOH solution to 500 mL of a 0.4 M HA originally at pH  = 5.0 ( pKa = 5.0)

Neglect the volume change.

Options:

a) 6.10

b) 5.09

c) 7.00

d) 5.02

Answer:

the final pH of a solution is 5.02

Option d) 5.02 is the Correct Answer

Explanation:

Given the data in the question,

Initially pKa = pH; so ratio is 1:1

thus, 0.4 M acid and base

Now, moles of NaOH = molarity × volume = 0.5 × 10 = 5 mmol = 5 × 10⁻³ mol.

Going into 500 mL ( 0.5 L ) of solution

new molarity will be;

⇒ moles / volume = 5 × 10⁻³ / 0.5 = 0.01 M

ACID reacting with BASE

original concentration of acid = 0.4 - 0.01 = 0.39 M

original concentration of base = 0.4 + 0.01 = 0.41 M

so

pH = 5 + log( base/acid)

= 5 + log ( 0.41/0.39)

= 5 + log ( 1.0512)

= 5 + 0.021

pH = 5.02

Therefore the final pH of a solution is 5.02

Option d) 5.02 is the Correct Answer

Answer:

Sanitize

Explanation:

Answer:

[tex]m=69.3kg[/tex]

Explanation:

Hello!

In this case, since the density is computed by dividing the mass of the substance by its occupied volume (d=m/V), we first need to realize that 0.8206 g/mL is the same to 0.8206 kg/L, which means we first need to compute the volume in L:

[tex]V=22.3gal*\frac{3.78541L}{1gal}=84.415L[/tex]

Then, solving for the mass in d=m/V, we get m=d*V and therefore the mass of gasoline in that full tank turns out:

[tex]m=0.8206g/L*84.415L\\\\m=69.3kg[/tex]

Best regards!

Answer:

have lower boiling points than alcohols of similar molecular weights.

Explanation:

Alkenes are hydrocarbons of the general molecular formula CnH2n. Alkenes are nonpolar hydrocarbons that are insoluble in water.

We must recall that alcohols are able to associate in water due to hydrogen bonding. This causes alcohols to have a relatively higher boiling point than alkenes of comparable molecular weight. Hencethe answer above.

7.53 × 10²³ molecules NaOH

Math

Pre-Algebra

Order of Operations: BPEMDAS

Chemistry

Atomic Structure

Step 1: Define

50.0 g NaOH

Step 2: Identify Conversions

Avogadro's Number

Molar Mass of Na - 22.99 g/mol

Molar Mass of O - 16.00 g/mol

Molar Mass of H - 1.01 g/mol

Molar Mass of NaOH - 22.99 + 16.00 + 1.01 = 40 g/mol

Step 3: Convert

Step 4: Check

Follow sig fig rules and round. We are given 3 sig figs.

7.5275 × 10²³ molecules NaOH ≈ 7.53 × 10²³ molecules NaOH

Answer:

sodium phosphide

Explanation:

Answer: 20.0 g of hydrogen chloride must simultaneously be formed

Explanation:

The balanced chemical reaction is :

[tex]NH_4Cl\rightarrow NH_3+HCl[/tex]

According to the law of conservation of mass, mass can neither be created nor be destroyed. The mass on reactant side must be equal to the mass on product side.

Thus mass of reactants = mass of products

Given : mass of ammonium chloride = mass of reactants = 29.4 g

mass of ammonia = 9.4 g

mass of products = mass of ammonia + mass of hydrogen chloride

9.4 g +mass of hydrogen chloride = 29.4 g

mass of hydrogen chloride = 20.0 g

Answer:

Please put question in!

Explanation:

Answer:

C) The law of conservation of matter

Explanation:

Conservation means keeping/ retaining something, in this case it is matter. Hope this helps!

Answer:

Explanation:

The first process is to draw out the heating curve to have a look at the transition possible which we've shown in the file below.

Now;

To find the energy removed to convert 75g steam → ice then comparing it with 215 kJ.

So conversion of steam at 125 °C → 100 °C

[tex]\Delta H = (75 \ g) (2.0 \ J/g^0C ) (125 - 100)^0 \ C[/tex]

[tex]\Delta H = 3750 \ J[/tex]

[tex]\Delta H = 3.75 \ kJ[/tex]

Since this is lesser than the energy given  (215 kJ), we then have to find the energy removed in the next phase.

For condensation of steam

Find the energy removed to change the steam from 100° C to liquid  at 100° C

[tex]\Delta H_2 = ( \dfrac{75 \ g}{18.02 \ g/mol}) (40.7 \ kJ/mol)[/tex]

[tex]\Delta H_2 =1.690* 10^ 2 \ J[/tex]

[tex]\Delta H_2 =169 \ kJ[/tex]

The total energy that is now removed from the system is:

[tex]\Delta H_1+ \Delta H_2 = (169 + 3.75) \ kJ[/tex]

[tex]\Delta H_1+ \Delta H_2 \simeq 173 \ kJ[/tex] which is still lesser than 215 kJ

To the third step; which is the conversion of water at 100° C → water at 0° C

[tex]\Delta H_3 = ( 75 \ g) (4.2 \ J/g^0 C)(100-0)^0C[/tex]

[tex]\Delta H_3 = 31500 \ J[/tex]

[tex]\Delta H_3 = 31.5 \ kJ[/tex]

Thus;

[tex]\Delta H_1+\Delta H_2+\Delta H_3 = (169 + 3.75 +31.5) \ kJ[/tex]

[tex]\Delta H_1+\Delta H_2+\Delta H_3 =204 \ kJ[/tex]

To the fourth step;

For freezing of water; we need to find the energy removed to change the water at 0° C → ice at 0° C

[tex]\Delta H_4 = (\dfrac{75 \ g}{18.02 \ g/mol})(6.02 \ kJ/mol)[/tex]

[tex]\Delta H_4 = 25.1 \ kJ[/tex]

∴

To change to the solid phase at 0° C; the total energy that is being removed from the steam is  

[tex]\Delta H_1+\Delta H_2+\Delta H_3 +\Delta H_4 =(169 + 3.75 + 31.5 +25.1) \ kJ[/tex]

[tex]\Delta H_1+\Delta H_2+\Delta H_3 +\Delta H_4 =229 \ kJ[/tex]

Here, the calculated total energy is more than the given energy 215 kJ.

This implies that the water is not fully converted to ice when 215 kJ of energy removal occurs, Hence the two phases that exist are liquid and solid.

Answer:

We need to add 900 mL of water.

Explanation:

To know the amount of water to add first we need to calculate the concentration of KOH when the pH is 12 and when is 11:

[tex] 14 = pH + pOH [/tex]

[tex] pOH = -log[OH] [/tex]

[tex] OH = 10^{-pOH} [/tex]

When pH = 12 (initial):

[tex]pOH_{i} = 14 - 12 = 2[/tex]

[tex]OH_{i} = 10^{-2}=0.01 M[/tex]

When pH = 11 (final):

[tex]pOH_{f} = 14 - 11 = 3[/tex]

[tex]OH_{f} = 10^{-3} = 0.001 M[/tex]

Now, by using the following equation we can find the volume of the solution to achieve a pH = 11:

[tex]C_{i}V_{i} = C_{f}V_{f}[/tex]

[tex]V_{f} = \frac{C_{i}V_{i}}{C_{f}} = \frac{0.01 M*100 mL}{0.001 M} = 1000 mL[/tex]

Finally, to bring 100 mL of the initial solution to 1000 mL we need to add the following amount of water:

[tex]1000 mL = V_{KOH} + V_{H_{2}O}[/tex]

[tex] V_{H_{2}O} = 1000 mL - V_{KOH} [/tex]

[tex] V_{H_{2}O} = 1000 mL - 100 mL = 900 mL [/tex]

Therefore, we need to add 900 mL of water.

I hope it helps you!            

The amount of water that needs to be added will be 900 mL

For finding the amount of water added we have to calculate the concentration of KOH at pH=12 and pH=11

[tex]14=pH+_pOH[/tex]

[tex]_pOH=-Log[OH][/tex]

[tex]OH=10^{-_pOH}[/tex]

[tex]_pOH_f=14-11=3[/tex]

When pH = 12 (initial):

[tex]_pOH_i=14-12=2[/tex]

[tex]_pOH_i=10^{-2}=0.01[/tex]

When pH = 11 (final):

[tex]_pOH_i=10^{-2}=0.01[/tex]

[tex]_pOH_f=14-11=3[/tex]

Now, by using the following equation we can find the volume of the solution to achieve a pH = 11:

[tex]C_iV_i=C_fV_f[/tex]

[tex]V_f=\dfrac{C_iV_I}{C_f} =\dfrac{0.01\times100}{0.001} =1000\ mL[/tex]

Finally, to bring 100 mL of the initial solution to 1000 mL we need to add the following amount of water:

[tex]1000=V_{KOH}+V_{H_2O}[/tex]

[tex]V_{H_2O}=1000mL-V_{KOH}[/tex]

[tex]V_{H_2O}=1000-100=900mL[/tex]

Thus the amount of water that needs to be added will be 900 mL

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