What ratio of NaCN to HCN is needed to prepare a pH 9.40 buffer? (Ka of HCN is 4.9 × 10⁻¹⁰)

Answers

Answer 1

Answer: The ratio of NaCN to HCN is, 1.26


Related Questions

different between methane and ethane.​

Answers

Methanol has a higher boiling point than ethane. The higher boiling point makes a much stronger attraction between molecules

PLEASE HELP ME ASAP!!!!!! YOU GET 10 POINTS!!!!!!
For reaction below, describe how its equilibrium could be shifted in the indicated direction.

1. H2(g)+C12(g)<---------->2HC1(g)+thermal energy: shift to the left

2.C(s) +O2(g)<---------->CO2+thermal energy: shift to the right

Answers

Answer:

Here is the ANSWER KEY, it may also has other of the questions you don't know :)

Explanation:

https://sciencewithhorne.weebly.com/uploads/5/7/3/5/57358947/unit_11_hw_key.pdf

classify the following elements under metals, non metals and metalloids, boron, zinc Mercury, silicon, oxygen, nitrogen, sodium​

Answers

Answer:

Zinc mercury transition metal

Silicon boron metalloid

Oxygen nitrogen non metal

Sodium alkali metal

Explanation:

Using standard formation enthalpies, calculate the standard reaction enthalpy for this reaction. 6CO2(g) + 6H2O(l)C6H12O6 + 6O2(g) ANSWER: kJ/mol

Answers

Answer:

2802.5 KJ/mol

Explanation:

Calculate standard enthalpy of the Reaction :

6CO2(g) + 6H2O(l)C6H12O6 + 6O2(g)

using standard formation enthalpies . hence the standard enthalpy of the reaction = 2802.5 KJ/mol

attached below is the detailed solution

If you form 3.28 moles of FeCl3 in a reaction, how many moles of FeCl2 did you start with? SHOW ALL WORK Plz

Answers

Answer:

molerat

Explanation:

Answer:

3.28 mol

Explanation:

2 mol FeCl3 forms from 2mol of FeCl2

therefore 3.28 mol of FeCl3 forms from=2/2×3.28 mol=3.28 mol

An airplane flies with an average speed of 600 km/hr. How much time will it take to travel 1950 km?

Answers

Time = distance ÷ speed

Time = 1950 ÷ 600

Time = 3.25 hours ( 3 hours 15 minutes )

helpppppppppppppp!!!!!!!!!!!!!how did chlorine atom attain saturation in potassium chloride and oxygen dichloride

Answers

It has a role as a fertilizer. It is a potassium salt and an inorganic chloride.

Work out the empirical formula of a compound that contains 35% of nitrogen , 5% of hydrogen and 60% of oxygen.

Answers

Answer:

[tex]H_5N_5O_6[/tex]

Explanation:

Hello there!

In this case, for the determination of empirical formulas, it is firstly necessary to assume the given percentages of the constituent atoms as the masses so we can compute their moles in the formula:

[tex]n_N=\frac{35gN}{14.01g/mol} =2.5molN\\\\n_H=\frac{5g}{1.01 g/mol}=5molH\\\\n_O=\frac{60g}{16 g/mol} =3molO[/tex]

Thus, we need to divide the resulting moles, by the fewest ones (those of nitrogen) in order to determine the coefficients in the formula:

[tex]N:\frac{2.5}{2.5}=1\\\\H:\frac{5}{2.5}=2\\\\O:\frac{3}{2.5} =1.2[/tex]

However, we need to turn all these numbers, whole numbers, so we multiply by 5 to get:

[tex]H_5N_5O_6[/tex]

Best regards!

Which of the nine substances are made of four elements?

Answers

Answer:

Oxygen mucury carbon dioxide and platinum

Explanation:

Help for extra points & brainlest !

Answers

Answer: i think is true

Explanation:

True. Cells have jobs in your body as they have functions to do.

What is needed to change a phase of matter?

Answers

The addition or subtraction of thermal energy. For example if you heat up an ice cube, it will melt to become water. If you heat it even more, it will evaporate.

Adaptations ONLY help an organism stay alive when they are physical and NOT when they are behavioral. true or false??

Answers

Answer:

true

Explanation:

i hope it's true, if not, then it's false, if anyone else answered but got it from the link, let me know to report it or you report it

Answer:

False.

Explanation:

Hibernation is an example of a physical adaptation. False.

Briefly describe each of the suns layers. I’ll give brainless

Answers

Answer:  The inner layers are the Core, Radiative Zone and Convection Zone.

The outer layers are the Photosphere, the Chromosphere, the Transition Region and the Corona.

Nuclear fusion of hydrogen in the core of the Sun produces tremendous amounts of energy that radiate out from the Sun.

The corona is the outermost layer of the Sun, starting at about 1300 miles (2100 km) above the solar surface (the photosphere). The temperature in the corona is 500,000 K (900,000 degrees F, 500,000 degrees C) or more.

The chromosphere is a layer in the Sun between about 250 miles (400 km) and 1300 miles (2100 km) above the solar surface (the photosphere). The temperature in the chromosphere varies between about 4000 K at the bottom (the so-called temperature minimum) and 8000 K at the top (6700 and 14,000 degrees F, 3700 and 7700 degrees C), so in this layer (and higher layers) it actually gets hotter if you go further away from the Sun, unlike in the lower layers, where it gets hotter if you go closer to the center of the Sun.

The photosphere is the deepest layer of the Sun that we can observe directly. It reaches from the surface visible at the center of the solar disk to about 250 miles (400 km) above that. The temperature in the photosphere varies between about 6500 K at the bottom and 4000 K at the top (11,000 and 6700 degrees F, 6200 and 3700 degrees C)

(phew! There you go!)

please help and show work
What is the volume of 5.7 moles of Hydrogen gas?

Answers

i thinkkkkk it’s 127.8 .

Helpp plzz..10pointss

Answers

Can you show me what the paragraph says, so I can help you please

Using the diagram, which two planes would intersect in HG?
Answer please .. :)

Answers

Answer:

I think D

Explanation:

it has both H and G in the planes.

1. Which of the following is not an example of a form of carbon?
O fullerenes
O graphite
salt
diamond

Answers

Salt diamond. Cuz those are mineral .

how many molecules are in 45.0 g of water

Answers

1.5055*10²³

Given mass = 45g
Molar mass of H2O = 2+16 = 18g

Moles = Given mass/Molar mass
= 45/18 = 2.5moles

No of molecule in 1 mole = 6.022*10²³
No of molecue in 2.5 mole = 2.5*6.022*10²³
= 1.5055*10²³

2KCIO3 -> 2KCI+ 302
How many moles of oxygen are produced by
the decomposition of 6.0 moles of potassium
chlorate, KCIO3?

Answers

Answer:

9 moles

Explanation:

The balanced chemical equation for this decomposition reaction is as follows:

2KCIO3 → 2KCI+ 302

Based on this equation, 2 moles of potassium chlorate (KCIO3) decomposes to form 3 moles of oxygen gas (O2).

Hence, 6 moles of pottasium chlorate will decompose to produce;

6 × 3 ÷ 2

= 18 ÷ 2

= 9 moles of O2.

the action force
According to Newton's third law of motion, a reaction force between two objects is
but in the opposite direction.
equal to
greater than
less than

Answers

Answer:

equal to - it's opposite but equal energy is the third law

how is salt obtained or manufactrured​

Answers

Answer:

There are three methods used to produce salt: solar, evaporation and rock mining.

Explanation:

Does a animal cell have cytolysis?

Answers

Answer:

The presence of a cell wall prevents the membrane from bursting,so cytolysis only occurs in animal and protozoa cells which do not have cell walls.

Explanation:


MgSO4 x 7H2O:

How
many molecules of
water are present
per magnesium
sulphate formulation
unit​

Answers

Answer:In regards to writing the formula, we know that magnesium has a charge of 1+ and sulfate, SO4, has a charge of 1-. Sulfate is a polyatomic ion so the charge of the whole thing is (SO4)1-. When you combine them you end up with MgSO4 and the "heptahydrate" is seven water molecules.

Explanation:

Answer:

Iduno sorry po hsjsnaka

precautions of a radioactive decay lab ?​

Answers

Answer:

Don't touch radioactive waste with bare hands

Don't eat the radioactive thing

Wear protective eyewear

Wear lab coat/gloves

Explanation:

https://ehs.princeton.edu/laboratory-research/radiation-safety/radioactive-materials/handling-radioactive-materials-safely

Princeton article

What is metal ? Where does it coke from ?

Answers

Answer:

Most pure metals, like aluminium, silver and copper, come from the Earth's crust. They are found in ores – solid materials called minerals, usually occurring in rock, from which the pure metal has to be extracted. The properties of pure metals can be improved by mixing them with other metals to make alloys.

a metal is an element that readily forms positive ions (cations) and has metallic bonds

coke is a strong stimulant made from coca leaves

CaC2(s) + 2H2O(l) --> Ca(OH)2(aq) + C2H2(g) In the reaction above, 0.5487 grams of calcium carbide are completely consumed to produce acetylene gas, C2H2. What volume (in mL) will this gas occupy if it is collected at 43 degrees Celsius and 0.926 atm pressure

Answers

Answer:

239.7mL

Explanation:

Using the general gas equation;

PV = nRT

Where;

P = pressure (atm)

V = volume (L)

n = number of moles (mol)

R = gas constant (0.0821 Latm/molK)

T = temperature (K)

The balanced chemical equation in this question is as follows:

CaC2(s) + 2H2O(l) --> Ca(OH)2(aq) + C2H2(g)

From the equation, 1 mole of CaC2 produces 1 mole of ethylene gas, C2H2.

Using mole = mass/molar mass

Molar mass of CaC2 = 40 + 12(2)

= 40 + 24

= 64g/mol

mole = 0.5487/64

mole = 0.00857mol of CaC2

Hence, 0.00857mol of CaC2 produced 0.00857mol of C2H2

Based on the information provided, n = 0.00857mol, T = 43°C = 43 + 273 = 316K, p = 0.926 atm

PV = nRT

V = nRT/P

V = 0.00857 × 0.0821 × 316/0.926

V = 0.222/0.926

V = 0.2397L

In mL, volume = 0.2397 × 1000

= 239.7mL

an element has atomic number of 17 state the elements group and period number​

Answers

Answer:

The element is in group 7, the halogens. The element is in the third period or row of the table.

Explanation:

Chlorine is element number 17.

what is a metal that forms two types of oxides and rusts in moisture​

Answers

Answer:

An example of a metal that rusts is Iron

Answer:

Iron

Explanation:

The metal that forms 2 types in moisture is iron.


How is a scientific law different from other laws in society?
A. A scientific law serves to protect people, property, and nature from
harm.
OB. A scientific law describes what always happens under specific
conditions in nature.
C. A scientific law is a rule about how to treat and punish people.
D. A scientific law is what scientists have decided should be forced
to happen in nature.

Answers

Answer:

B. A scientific law describes what always happens under specific

conditions in nature.

Explanation:

Scientific law is something that has been proven over and over and therefore is always correct under conditions in nature.

Answer:

B. A scientific law describes what always happens under specific

conditions in nature.

Explanation:

Scientific law is based on observation and experiments to support a claim. It usually describes nature.  

what is the function of a prism

Answers

Answer:

Prisms are sometimes used for the internal reflection at the surfaces rather than for dispersion. If light inside the prism hits one of the surfaces at a sufficiently steep angle, total internal reflection occurs and all of the light is reflected.

Explanation:

Prism, in optics, piece of glass or other transparent material cut with precise angles and plane faces, useful for analyzing and reflecting light. An ordinary triangular prism can separate white light into its constituent colours, called a spectrum.

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