Does anybody know these questions ?

Answer:

205mL of 0.140M KF solution

Explanation:

pH = 2.70 solution.

It is possible to obtain the pH of the buffer of HF-KF using the H-H equation:

pH = pKa + log [KF] / [HF]

Where pH is desire pH = 2.70

pKa is pKa of HF = 3.17

[KF] could be taken as moles of KF

And [HF] moles of HF: 400.0mL = 0.4L * (0.212mol/L) = 0.0848 moles of HF

Replacing:

2.70 = 3.17 + log [KF] / [0.0848 moles HF]

-0.47 = log [KF] / [0.0848 moles HF]

0.3388 = [KF] / [0.0848 moles HF]

[KF] = 0.02873 moles of KF must be added.

In mL using concentration of KF (0.140M):

0.02873 moles KF * (1L / 0.140 mol) = 0.205L =

Answer:

Metals shows the property of malleability while non-metals are non-malleable. Metals are generally those substances that have a shiny surface and thus are lustrous. Whereas non-metals have non-shiny appearance and thus falls under the category of non-lustrous substances.

Explanation:

hope the answer was helpful

Answer:

I think its b

Explanation:

well because thermal energy its connected to kidnetic energy

Answer:

D

Explanation:

My favorite pancake recipe

2 cups all purpose | plain flour, (290 g | 10 oz)

1/4 cup granulated sugar or sweetener, (60g | 2 oz)

4 teaspoons baking powder

1/4 teaspoon baking soda

1/2 teaspoon salt

1 3/4 cups milk, (440ml)

1/4 cup butter, (60g | 2 oz)

2 teaspoons pure vanilla extract

1 large egg

Combine everything in a bowl (separate wet and dry) and cook at medium low heat until it is brown and there are bubbles on top. Then serve with syrup. Good luck!!!

Balanced chemical equation :

[tex]2NH_3(aq)+AgCl(s) ->Ag(NH_3)_2^+(aq) + Cl^-(aq)[/tex],  [tex]K_{sp}=2.9\times 10^{-3}[/tex]

So, solubility product will be equal to [tex]K_{sp}[/tex] :

[tex]K_{sp}=\dfrac{[Ag(NH_3)_2^+][Cl^-]}{[NH_3]^2}\\\\2.9\times 10^{-3}=\dfrac{S.S}{(1.6-2S)^2}[/tex]

Solving above we get :

S = 0.041

Therefore, solubility of silver chloride is 0.041 .

Hence, this is the required solution.

Answer:

Nonmetals form negative ions (anions). A nitrogen atom must gain three electrons to have the same number of electrons as an atom of the following noble gas, neon. Thus, a nitrogen atom will form an anion with three more electrons than protons and a charge of 3−.

Explanation:

have advanced

Answer:

a. Boron trifluoride

b. Propane

c. Dinitrogen pentoxide

d. Carbon Dioxide

e. Silicon Octafluroride?

Explanation:

Glad to help :)

Answer:

Fair test.

PLS GIVE BRAINLIEST

Answer:

i hope this helps

Magma in the Earth's mantle moves in convection currents. The hot core heats the material above it, causing it to rise toward the crust, where it cools. The heat comes from the intense pressure on the rock, combined with the energy released from natural radioactive decay of elements.

Explanation:

Explanation:

Given parameters:

Number of moles of Cu  = 0.696mol

Volume of HNO₃  = 146mL

Concentration of HNO₃  = 5.5M

Unknown:

Will Cu react completely = ?

Limiting reagent  = ?

Remaining mass of the compound  = ?

Solution:

The equation of the reaction is given as;

             Cu + 4HNO₃  →  Cu(NO₃)₂  + 2H₂O  + 2NO₂

Let us find the number of moles of HNO₃ ;

  Number of moles  = concentration x volume

  Number of moles  = 5.5 x 146 x 10⁻³L = 0.803mol

From the balanced reaction equation;

      1 mole of Cu reacted with 4 mole of HNO₃

       0.696 mole of Cu will require 4 x 0.696  = 2.784mole of HNO₃

So, the limiting reactant is HNO₃ because it is in short supply.

Cu will completely react

Mass of the remaining compound we need;

       mass  = number of moles x molar mass

  Number of moles = 2.784  - 0.803  = 1.981mole

So, mass  = 1.981 x (1 + 14 + 3(16))  = 124.81g of HNO₃ is required to make the reaction complete.

The limiting reagent is HNO3 and the remaining compound in mass is 25.1 grams of Cu.

The reaction taking place in the given case is,

Based on the given information,

• The moles of Cu given is 0.696 moles.  

• The volume of HNO3 given is 146 ml and the molarity of HNO3 is 5.5 M.

Now the moles of HNO3 can be determined as,

[tex]Moles = \frac{M1V1}{1000} \\Moles = \frac{5.5M*146 ml}{1000} \\Moles = 0.803 moles[/tex]

• In order to find the limiting reagent, there is a need to divide moles by their stoichiometric coefficient, that is,  

Cu = 0.696/3 = 0.232 moles and HNO3 = 0.803/8 = 0.100 moles

• As the moles of HNO3 is present in less amount, therefore, HNO3 will be the limiting reagent.  

Now the remaining copper left in the reaction will be,

[tex]= 0.696-\frac{3}{8} *0.803\\= 0.696-0.300\\= 0.396 moles[/tex]

Now the mass of remaining copper will be = Moles * Molecular mass of Cu

[tex]Mass = 0.396 moles * 63.5 g/mol\\Mass = 25.1 g[/tex]

Thus, the mass of remaining compound is 25.1 grams and the limiting reagent is HNO3.

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Answer: Bb

Explanation:

The capital B (purbred black fur) is domaint the the lower case b(purebred white fur)

The concentration, mass/volume percent (m/v) : 1.98%

[tex]\tt \%m/v=\dfrac{mass~solute}{volume~of~solution}\times 100\%[/tex]

mass solute = mass of NaCl = 30 g

volume of solution = volume of water + volume of NaCl

volume of water = 1.5 L = 1500 ml

volume of NaCl :(density = 2.16 g/ml)

[tex]\tt V=\dfrac{30}{2.16}=13.8~ml[/tex]

volume of solution :

[tex]\tt 1500+13.8=1513.8~ml[/tex]

the concentration (%m/v) :

[tex]\tt \dfrac{30}{1513.8}\times 100=1.98\%[/tex]

Answer:

7

Explanation:

Answer:

m

Explanation:

Answer:

93.5 kPa

Explanation:

Step 1: Given data

Step 2: Convert the temperatures to the Kelvin scale

When working with gases, we need to consider the absolute temperature. We will convert from Celsius to Kelvin using the following expression.

K = °C + 273.15

T₁: K = 50°C + 273.15 = 323 K

T₂: K = 100°C + 275.15 = 373 K

Step 3: Calculate the final pressure of the gas

At a constant volume, we can calculate the final pressure of the gas using Gay-Lussac's law.

P₁/T₁ = P₂/T₂

P₂ = P₁ × T₂/T₁

P₂ = 81.0 kPa × 373 K/323 K

P₂ = 93.5 kPa

Answer:

7 valence e-, obtain e-, negative

Answer:

Watch Naruto that's the answer

Explanation:

Answer:

Explanation:

no of moles of C2H6=10/30=0.33

complete combustion of 2 moles of ethane produce 4 moles of CO2 therefore 0.33 moles of C2H6 produced 0.66 moles of CO2

now moles =given mass/molar mass

mass= moles*molar mass

mass of CO2=0.67*44=29.48 g

KOH added : 7.5 ml

Buffer solution of weak acid HCOOH and strong base KOH

Reaction

initial = 100 ml 0.1 M HCOOH = 10 ml mol HCOOH, and x mlmol of KOH

KOH + HCOOH ⇒ COOHK + H₂O

  x           10

  x            x                 x              x

  -            10-x             x              x

[HCOO - ] = 3[HCOOH]

[tex]\tt \dfrac{x}{x+100~ml}=3\dfrac{10-x}{x+100}\\\\x=3(10-x)\\\\x=30-3x\\\\4x=30\rightarrow x=7.5~ml[/tex]

666

Explanation:

nhgytfghgtfgv

Answer:a compound

Explanation:

Answer:

[tex]V_{base}=9.442mL[/tex]

Explanation:

Hello!

In this case, when acetic acid is titrated with sodium hydroxide, the following chemical reaction is carried out:

[tex]CH_3COOH+NaOH\rightarrow CH_3COONa+H_2O[/tex]

Whereas there is a 1:1 mole ratio between the acid and the base, which means that at the equivalence point we evidence:

[tex]n_{acid}=n_{base}[/tex]

Which in terms of volumes and concentrations is written as:

[tex]M_{acid}V_{acid}=M_{base}V_{base}[/tex]

Thus, solving for the required volume of base, we obtain:

[tex]V_{base}=\frac{M_{acid}V_{acid}}{M_{base}}=\frac{0.1894M*10.00mL}{0.2006M}\\\\ V_{base}=9.442mL[/tex]

Best regards!

Answer:

Salt water is classified as a mixture.

Explanation:

Answer:

Vinegar contains acetic acid which removes this coating. When the protective coating is removed, oxygen in the atmosphere can reach the iron in the steel wool and a chemical reaction called oxidation occurs. ... This reaction is also an exothermic reaction. It creates heat energy

Explanation:

hope this helps u

Vinegar incorporates acetic acid which gets rid of this coating. When the defensive coating is removed, oxygen in the environment can reach the iron in the metal wool and a chemical reaction called oxidation occurs. This reaction is additionally an exothermic reaction. It creates warmth energy.  

Hope it helped! Have a nice day! <3

Answer:

1.1 M

General Formulas and Concepts:

Explanation:

Step 1: Define variables

1.2 mol KCL

1.1 L of solution

M = unknown

Step 2: Solve for Molarity

Step 3: Check

We are given 2 sig figs. Follow sig fig rules.

1.09091 M ≈ 1.1 M

Answer:

1.9998 atm

Explanation:

Balance the equation and then use PV=nRT to find the variable.

The final pressure of the chamber is 2 atm.

The given parameters;

The balanced chemical reaction of the given elements;

[tex]O_2 \ \ + \ 2H_2 \ \ ---> \ 2H_2O[/tex]

Initial number of moles of the gases, = 1 + 2 = 3 moles

Final number of moles of the product, = 2  moles

The final pressure of the chamber is calculated as follows;

[tex]PV = nRT\\\\\frac{P}{n} = \frac{RT}{V} \\\\\frac{P_1}{n_1} = \frac{P_2}{n_2} \\\\P_2 = \frac{P_1 n_2}{n_1} \\\\P_2 = \frac{3 \times 2}{3} \\\\P_2 = 2 \ atm[/tex]

Thus, the final pressure of the chamber is 2 atm.

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Answer:

[tex]\boxed {\boxed {\sf882 \ Joules}}[/tex]

Explanation:

Potential energy can be found by multiplying the mass by the height by the gravitational acceleration.

[tex]PE=mgh[/tex]

The mass is 45 kilograms. The height is 2 meters. The gravitational acceleration on Earth is 9.8 meters per seconds squared.

[tex]m=45 \ kg \\h= 2 \ m \\g=9.8 \ m/s^2[/tex]

Substitute the values into the formula.

[tex]PE=45 \ kg * 2 \ m * 9.8 m/s^2[/tex]

Multiply.

[tex]PE=441 kg*m/s^2*2 \ m[/tex]

[tex]PE= 882 \ kg *m/s^2 *m[/tex]

1 kg*m/s^² is equal to 1 Newton (N). Substitute N in for kg*m/s²

[tex]PE=882 \ N*m[/tex]

1 Newton meter (N*m) is equal to 1 Joule (J). Our current answer is equivalent to 882 Joules.

[tex]PE= 882 \ J[/tex]

The sled's potential energy is 882 Joules.

Answer:

882 J

Explanation:

Answer:

c or d

Explanation:

i tried a and it was wrong. its not B. and i cant see the rest. its the one that looks like a catipillar tho

Answer:

Its not A or B

Explanation:

Answer: Collision theory explains why different reactions occur at different rates, and suggests ways to change the rate of a reaction. Collision theory states that for a chemical reaction to occur, the reacting particles must collide with one another. The rate of the reaction depends on the frequency of collisions. The theory also tells us that reacting particles often collide without reacting. For collisions to be successful, reacting particles must (1) collide with (2) sufficient energy, and (3) with the proper orientation.

Molecules must collide before they can react

This rule is fundamental to any analysis of an ordinary reaction mechanism. It explains why termolecular processes are so uncommon. The kinetic theory of gases states that for every 1000 binary collisions, there will be only one event in which three molecules simultaneously come together. Four-way collisions are so improbable that this process has never been demonstrated in an elementary reaction.

Explanation:hope this helped

If two reactant molecules collide but do not have the right alignment then formation of product does not takes place.

Collision theory states that if reacting particles frequently collide without reacting. Reacting particles must collide with sufficient energy and the right orientation for collisions to be successful.

So it the two reactant molecules collide with each other without proper orientation then it will not convert into products.

Hence formation of product will not takes place if reactant does not collide with right allignment.

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