An aqueous solution contains 0.30 M potassium cyanide. One liter of this solution could be converted into a buffer by the addition of:

Answers

Answer 1

Answer:

Hydrocyanic acid, HCN.

Explanation:

A buffer is defined as the aqueous mixture of a weak acid and its conjugate base. Or a weak base and its conjugate acid. In the problem, we have a solution of potassium cyanide. The conjugate acid of potassium cyanide is hydrocyanic acid. A weak acid with pKa = 9.89.

That means, to convert the solution into a buffer we must add:

Hydrocyanic acid, HCN.

Related Questions

For a science project, Janet performs four experiments that are supposed to show a chemical reaction. She displays her results in a table.A 4-column table with 4 rows. The first column titled experiment has entries 1, 2, 3, 4. The second column titled substances has entries water + heat, vinegar + baking soda, cabbage juice + lemon juice, liquid A + liquid B. The third column titled evidence of reaction has entries gas formation, gas formation, color change, precipitate formation. The fourth column titled Chemical Reaction ? has entries yes, yes, yes, yes.In the column titled "Chemical reaction?,” which experiment’s data should be changed to "No”?Experiment 1Experiment 2Experiment 3Experiment 4

Answers

Answer:

Experiment 1

Explanation:

I don’t know if this is right

Which reaction represents a double replacement reaction?
A
C2H4 + 302 --> 2CO2 + 2H2O
B
NH3 + H20 --> NH4OH
с
CuBr2 + 2K --> 2KBr + Cu
D
2FeCl3 + 3Na2CO3 --> Fe2(CO3)3 + 6Naci

Answers

Answer:

D

Explanation:

D shows a double displacment reaction

the other ones show combustion, synthesis and single displacment

Look at the reaction below. Upper H subscript 2 upper S upper O subscript 4 (a q) plus upper C a (upper O upper H) subscript 2 (a q) right arrow upper C a upper S upper O subscript 4 (a q) plus 2 upper H subscript 2 upper O (l). Which substance is the base in the reaction? A. 2H2O (l) B. H2SO4 (aq) C. CaSO4 (aq) D. Ca(OH)2 (aq)

Answers

Answer:

Its D  

Explanation:

Did it on edge

According to the reaction: H₂S0₄ + Ca(OH)₂ → CaSO₄+ 2H₂O, the base is Ca(OH)₂.

What is a base?

Base is defined as a substance which can accept protons or any chemical compound that yields hydroxide ions (OH-) in solution.

Generally, base are substances that produces hydroxide ion when dissolve in water.  

Base are substances that reacts with acid to produce salt and water. Example of base includes sodium hydroxide, potassium hydroxide, magnesium hydroxide, calcium hydroxide etc.

Therefore, according to the reaction:

H₂S0₄ + Ca(OH)₂ → CaSO₄+ 2H₂O

The base is Ca(OH)₂.

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Calculate the volume of an
object with dimensions
measuring:
9.0 mm x 2.0 mm x 2.0 mm
[ ? ] mm3

Answers

Answer:

9.0mm x 2.0mm x 2.0mm

= 18mm3

Answer:

36mm^3

Explanation:

This is easy

Alcohols have more hydrogen bonding .
(True or False) ?!​

Answers

Answer:

True

Explanation:

An alcohol is an organic molecule containing an -O-H group. Any molecule which has a hydrogen atom attached directly to an oxygen or a nitrogen is capable of hydrogen bonding.

students investigating how gravity affects balls of different sizes, is this a good experiment?

Answers

Answer:

yea

Explanation:

Answer:1.Owen

2.By dropping the balls from the same height

3.She dropped the balls from different heights

4. Perform a second trial

Explanation: sub to technoblade plz

Calculate the molecular mass of sodium trioxocarbonate (iv) decahydrate​

Answers

Answer:

106.180

Explanation:

maybe this is the correct answer

I SAID MAYBE

NEED HELP ASAP!!!.....Which is not true about the ionic compound sodium chloride (NaCl)? A.)it was formed when electrons were shared B.)it is electrically neutral C.)it has properties different from the atoms from which it is formed D.)it is a white crystalline solid​

Answers

(a) it was formed when electrons were shared

NaCl is an ionic bond which means an electron(s) was transferred (from one atom to another to make them stable) not a covalent bond which means an electron(s) was shared

g how many moles of NO are produced if 2.5 mol of O2 react completely with 4.0 mol of NH3 (molar mass of NO

Answers

Answer:

2 moles of NO

Explanation:

Our reaction is:

4NH₃ + 5O₂  →   6H₂O  +  4NO  

4 moles of ammonia react to 5 moles of oxygen in order to produce 6 moles of water and 4 moles of NO

We need to determine the limiting reactant:

Ratio is 4:5, As 4 moles of ammonia react to 5 moles of oxygen and we have 4 moles, we definetely need 5 moles, but the problem is, we only have 2.5 moles of O₂. Oxygen is the limting reagent.

5 moles of O₂ produce 4 moles of NO, according to stoichiometry

2.5 moles of O₂ may produce (2.5 . 4) / 5 = 2 moles of NO


In an experiment, a student was assigned to find the formula of an unknown hydrate that weighed 15.67g. The anhydrate, XCO3 (molar mass = 84.32 g/mol), weighed 7.58 g after all the water was driven off. Determine the moles of water per one mole of anhydrate.

Answers

Answer:

5.0 moles of water per one mole of anhydrate

Explanation:

To solve this question we must find the moles of the anhydrate. The difference in mass between the dry and the anhydrate gives the mass of water. Thus, we can find the moles of water and the moles of water per mole of anhydrate:

Moles Anhydrate:

7.58g  * (1mol / 84.32g) = 0.0899 moles XCO3

Moles water:

15.67g - 7.58g = 8.09g * (1mol / 18.01g) = 0.449 moles H2O

Moles of water per mole of anhydrate:

0.449 moles H2O / 0.0899 moles XCO3 =

5.0 moles of water per one mole of anhydrate

hydrogen iodide is not produced by the same method is for hydrogen chloride why with reaction​

Answers

Using Phosphoric acid will work perfectly for producing Hydrogen halides because its not an Oxidizing agent. ...

Using an ionic chloride and Phosphoric acid

H3PO4 + NaCl ==> HCl + NaH2PO4

H3PO4 + NaI ==> HI + NaH2PO4

H2SO4 + NaCl ==> HCl + NaHSO4

This method(Using H2So4) will work for all hydrogen hydrogen halide except Hydrogen Iodide and Hydrogen Bromide.

The Sulphuric acid won't be useful for producing Hydrogen Iodide because its an OXIDIZING AGENT. Whist producing the Hydrogen Iodide... Some of the Iodide ions are oxidized to Iodine.

2I-² === I2 + 2e-

What types of reactions are these 3 chemical equations?-
*2Kl+Pb(NO3)2=PbI2+2KNO3
*2Al+3CuSO4=Al2(SO4)3+3Cu
*C2H5OH+3O2=2CO2+3H2O

Answers

Answer:

*2Kl+Pb(NO3)2=PbI2+2KNO3: double replacement.

*2Al+3CuSO4=Al2(SO4)3+3Cu: single replacement.

*C2H5OH+3O2=2CO2+3H2O: combustion.

Explanation:

Hello there!

In this case, according to the required, it turns out necessary for us to recall the five types of reactions, combination, decomposition, single and double replacement and combustion as shown on the attached figure.

In such a way, since the first reaction follows the pattern AB+CD-->AD+CB we infer it is double replacement; the second reaction follows the patter A+BC-->AC+B and therefore it is single replacement; and the last one follows the pattern of combustion reaction due to the presence of CO2 and H2O on the products side.

Regards!

The idea that light can act like packets led to what new field on science?

Answers

Light acting as 'packets' of exact amounts of energy (a particle-like quality) called quanta led to the development of quantum mechanics. Light also has wave qualities (wavelength, frequency, amplitude) which is referred to as particle-wave duality.

Answer is quantum mechanics

Quantum mechanics deals with light and really small particles

Chemical properties of an element are primarily dependent upon Group of answer choices the electron configuration of the element atomic weight of the element the number of main energy levels (electron shells) of the element the number of electrons in the innermost shell of the atom

Answers

Answer:

The answer is "the electron configuration of the element".

Explanation:

Electronics are distributed in atomic and molecular orbit via electrons from an atom or a molecule.

It reflects a most frequent dependence on valence electrons in the outer.

Through analyzing the context of the regular periodic table, the individual atoms are helpful. That's also important to understand chemical connections, which hold electrons together. This similar approach helps to explain the specific characteristics of lasers or semiconductors for bulk materials.

If more powdered Kool-Aid is added to the same amount of water, what happens to the solution (the answer I clicked I don’t know if correct or not)

Answers

Answer:

its option 3

Explanation:

the molarity of the solution increases

If more powdered Kool-Aid is added to the same amount of water, then the molarity of the solution increases because there are more solute particles in the solution.

What is Molarity?

Molarity of a given solution is known as the total number of moles of solute per litre of the solution.  A solution that is 1.00 molar (written 1.00 M) contains 1.00 mole of solute for every liter of solution.

Molarity = (No. of moles of solute ÷ Volume of solution in liters)

The unit of molarity is mol L⁻¹.

Molarity is temperature dependent because as temperature changes, volume of the solution also changes.

Therefore, If more powdered Kool-Aid is added to the same amount of water, then the molarity of the solution increases because there are more solute particles in the solution.

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Calculate the percent composition by mass (to 4 significant figures) of all the elements in calcium phosphate [Ca3(PO4)2], a major component of bone.

Answers

Answer:

The elements present in calcium phosphate-based on molecular formula are calcium, phosphorus, and oxygen. The molecular mass of Ca or calcium is 40.08 grams per mole, the molecular mass of P or phosphorus is 30.97 grams per mole, and the molecular mass of oxygen is 16.00 grams per mole. So, in combination, the molecular mass of Ca₃(PO₄)₂ is, = (3 × 40.08 + 2 ×3 0.97 + 8 × 16) = 310.18 grams per mole

Now, the mass percent of calcium is, = n × molecular mass of calcium/ molecular mass of Ca₃(PO₄)₂ × 100% = 3 × 40.08 / 310.18 × 100 = 38.76 % Thus, the mass percent of the calcium in calcium phosphate is 38.76%.  

The mass percent of phosphorus (P), = n × molecular mass of phosphorus/molar mass of Ca₃(PO₄)₂ × 100% = 2 × 30.97/310.18 × 100 = 19.97% Thus, the mass percent of phosphorus in calcium phosphate is 19.97%.  

The mass percent of oxygen (O), = n × molecular mass of oxygen/molar mass of Ca₃(PO₄)₂ × 100% = 8 × 16/310.18 × 100% = 41.27% Thus, the mass percent of oxygen in calcium phosphate is 41.27%.

Help plz:)))I’ll mark u Brainliest

Answers

Explanation:

LCCEB is the answer


How many grams of oxygen are necessary to react completely if you have 4.0 moles of oxygen

Answers

Answer:

1.3 × 10² g

Explanation:

Step 1: Given data

Moles of oxygen: 4.0 mol

Step 2: Calculate the mass corresponding to 4.0 moles of oxygen

For a given chemical reaction, we need 4.0 moles of oxygen and we want to find what mass in grams it represents. To convert moles to mass, we need a conversion factor: the molar mass. The molar mass of oxygen is 32.00 g/mol.

4.0 mol × 32.00 g/mol = 1.3 × 10² g

if 19.1 mL of 1.26 M HBr is headed to 23.7g of CAC03 what volume of CO2 would be produced as 713.6 torr and 29.9°C

Answers

Answer:

0.32 L

Explanation:

The equation of the reaction is;

2HBr(aq) + CaCO3(s) ----->CaBr2(aq) + H2O(l) + CO2(g)

The number of moles HBr reacted = 19.1/1000 L * 1.26 M = 0.024 moles

According to the reaction equation;

2 moles of HBr produces 1 mole of CO2

0.024 moles of HBr produces  0.024 * 1/2 = 0.012 moles of CO2

For CaCO3

Number of moles  = 23.7g/100 g/mol = 0.237 moles

Since the reaction is 1:1, 0.237 moles of CO2 is produced.

Hence HBr is the limiting reactant and 0.012 moles of CO2 is produced.

From PV =nRT

V = nRT/P

P= 713.6 torr

n= 0.012 moles

T = 29.9°C + 273 = 302.9 K

R =  62.36 L torr/mol K

V = 0.012 * 62.36 * 302.9/713.6

V = 0.32 L

Find the horizontal range of a projectile launched at 15 degrees to the horizontal with speed of 40m/s​

Answers

To Find :

The horizontal range of a projectile launched at 15 degrees to the horizontal with speed of 40 m/s​.

Solution :

The horizontal range of a projectile is given by :

[tex]R = \dfrac{u^2 sin 2\theta}{g}[/tex] ( Here, g is acceleration due to gravity = 10 m/s² )

Putting all value in above equation :

[tex]R = \dfrac{40^2 \times sin (2 \times 15)}{10} \ m\\\\R = \dfrac{1600 \times 1}{2\times 10} \ m\\\\R = 80 \ m[/tex]

Therefore, the horizontal range of projectile is 80 m.

The carbon-oxygen double bond, or carbonyl, is a key feature of many organic molecules. Two resonance structures can be used to illustrate the properties of the carbonyl structure as provided. In analyzing the minor resonance structure, what can we conclude about the Lewis acid properties of the carbonyl

Answers

The question is incomplete, the complete question is shown in the image attached to this answer

Answer:

B

Explanation:

A Lewis acid is specie that has vacant orbitals and is able to accept a lone pair of electrons while a Lewis base is any specie having a lone pair of electrons which can be donated to another chemical specie.

Hence a Lewis acid accepts a lone pair of electrons while a Lewis base donates a lone pair of electrons.

From the resonance structure shown, the carbon atom in the carbonyl compound ought to function as the Lewis acid since it is electrophilic (electron deficient).

Answer: The Carbon atom in the carbonyl will act as a lewis acid and will accept a pair of electrons

Explanation:

In the minor resonance structure for the carbonyl group, we observe a positive formal charge on the carbon atom. Because of its positive formal charge, the carbon atom will act as a Lewis acid and accept a pair of electrons to stabilize that formal charge.

Does the addition of a catalyst affect the ΔH of reaction?

Answers

Answer:

no

Explanation:

because its just no lol.

What is the molarity and normality of solution containing 80 g of NaOH dissolved in 2.0 liter of the solution?

Answers

AAnswer:

Explanation:

yclohexane (C6H12) is soluble in benzene (C6H6) and insoluble in water. This is because benzene has a

Answers

Answer:

Cyclohexane (C6H12) Is Soluble In Benzene (C6H) And Insoluble In Water. This Is Because Benzene Has A Lower Density Than Water Lower Heat Capacity Than Water Lower Boiling Point Than Water Lower Polarity Than Water.

Cyclohexane is insoluble in water solvents, but it is soluble in Benzene, because it is a nonpolar Solvent.

Why cyclohexane dissolves in Benzene but not in water?

Solubility in chemistry depend upon the nature of the solvent and the solute "like dissolves like".

Cyclohexane  and  Benzene both  are  a nonpolar solute  and only dissolve in nonpolar solvent.

Hence, water is a polar solvent cyclohexane  it is not soluble in water.

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The stream table shows the time needed for water to soak into the playfield soil.

Answers

Answer:

TRUE

Explanation:

plz brian list

Answer:

True

Explanation:

How many liters of carbon dioxide gas are produced from 0.012 moles oxygen and excess propane at STP? 1 C3H8 (g) + 5 O2 (g) → 3 CO2 (g) + 4 H2O (g) ______ Liters CO2

Answers

Answer:

0.16 L

Explanation:

Step 1: Write the balanced equation

C₃H₈(g) + 5 O₂(g) → 3 CO₂(g) + 4 H₂O(g)

Step 2: Calculate the moles of CO₂ produced from 0.012 moles of O₂

The molar ratio of O₂ to CO₂ is 5:3. The moles of CO₂ produced are 3/5 × 0.012 mol = 0.0072 mol.

Step 3: Calculate the volume occupied by 0.0072 moles of CO₂ at standard temperature and pressure

At STP, 1 mole of CO₂ occupies 22.4 L.

0.0072 mol × 22.4 L/1 mol = 0.16 L

ved:

Chapter

Chapter List

CH5.3

Problem

Problem List

10SMB

Printed circuit boards are used in the electronics industry to both connect and hold components in place. In production, 0.03 in. of copper foil is laminated to an insulating plastic board. A circuit pattern made of a chemically resistant polymer is then printed on the board. Next, the unwanted copper is chemically etched away by using selected reagents. If copper is treated with Cu(NH3 ) 4Cl2 (cupric ammonium chloride) and NH4OH (ammonium hydroxide), the products are water and Cu(NH3) 4Cl (cuprous ammonium chloride). Once the copper is dissolved, the polymer is removed by solvents, leaving the printed circuit ready for further processing. If a single-sided board 4 in. by 8 in. is to have 75% of the copper layer removed using these reagents, how many grams of each reagent will be consumed? Data: The density of copper is 8.96 g/cm3.​

Answers

ladoooooooooioooooioiiioooo

Consider a hypothetical metal that has a density of 3.55 g/cm3, an atomic weight of 40.48 g/mol, and an atomic radius of 0.135 nm. Compute the atomic packing factor if the unit cell has tetragonal symmetry, values for the a and c lattice parameters are 0.545 and 0.255, respectively.

Answers

Answer:

0.5447

Explanation:

The atomic packing fraction factor is given by

APF = Volume of sphere/ Volume of unit cell

[tex]APF = \frac{N\times V_N}{V_C}[/tex]

The atomic radius = 0.135 nm

The Density of the metal = 3.55 g/cm^3

To calculate the number of atoms

= desnsity/(atomic radius×Avagadro's number)

Putting values and solving we get

the number of atoms = 4

Now,

[tex]APF = \frac{4\times 4/3\pi(0.135\times10^{-9})^3}{(0.545\times10^{-9})^2(0.255\times10^{-9})}[/tex]

Solving we get

APF = 0.54427


2H2 + O2 2H20
How many moles of oxygen are consumed if 8 moles H2 are used?

Answers

Answer:

4 moles of O2 are consumed if 8moles of H2

Question 1
Where does photosynthesis happen in a plant cell?
O Cell membrane
O Cell wall
O Chloroplast
O Mitochondria

Answers

Answer:

Chloroplast

Explanation:

Photosynthesis happens in chloroplast of plants. Mitochondira is where the cellular respiration happens.

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