Pl help it’s for a grade

Answer:

2Na2S + Cd(NO3)2 ---> CdS + 2NaNO3

The coefficients therefore are 1,1,1&2

Answer:

Q1 is A.

Q2 is right

Q3 is D.....I dont

really know about this one

Q4 is right

Answer:

pH = 10.11

Explanation:

Hello there!

In this case, since it is possible to realize that this base is able to acquire one hydrogen atom from the water:

[tex]C_{18}H_{21}NO_4+H_2O\rightleftharpoons C_{18}H_{21}NO_4H^+OH^-[/tex]

We can therefore set up the corresponding equilibrium expression:

[tex]Kb=\frac{[C_{18}H_{21}NO_4H^+][OH^-]}{[C_{18}H_{21}NO_4]}[/tex]

Which can be written in terms of the reaction extent, [tex]x[/tex]:

[tex]Kb=\frac{x^2}{0.00500M-x}=3.39x10^{-6}[/tex]

Thus, by solving for [tex]x[/tex] we obtain:

[tex]x_1=-0.000132M\\\\x_2=0.0001285M[/tex]

However, since negative solutions are now allowed, we infer the correct [tex]x[/tex] is 0.0001285 M; thus, the pOH can be computed:

[tex]pOH=-log(x)=-log(0.0001285)=3.89[/tex]

And finally the pH:

[tex]pH=14-pOH=14-3.89\\\\pH=10.11[/tex]

Best regards!

Answer:

69420

Explanation:

Answer:

We need to calculate number atoms, which can be determined as follows: We know that 1 mol contains 6.02214076×1023 number of atoms. i.e. is Avogadro's constant. Therefore the answer to the above question is that the number of atoms in 3.5 mol of Arsenic is 2.11×104 number of atoms.

Explanation:

Answer:

Explanation:

Calcium is all around us. The average human contains approximately 1kg of calcium, of which 99% is stored in our bones. It is the 5th most abundant element in the earth's crust, occurring widely as calcium carbonate which is more commonly known as limestone. It is also the fifth most abundant dissolved ion in seawater.

Answer:

3

Explanation:

Answer:

Their vibrating particles are packed together in relatively fixed positions.

Explanation:

As you can see in the image below, solid is packed together.

Answer: The concentration of hydrogen ions is [tex]10^{-11}M[/tex] and the concentration of hydroxide ions is [tex]10^{-3}M[/tex]. Thus the concentration of hydroxide ions is more than the concentration of hydrogen ions.

Explanation:

pH or pOH is the measure of acidity or alkalinity of a solution.

pH is calculated by taking negative logarithm of hydrogen ion concentration.  

[tex]pH=-\log [H^+][/tex]

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

Putting in the values:

[tex]11=-\log[H^+][/tex]

[tex][H^+]=10^{-11}M[/tex]

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

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

[tex]3=-log[OH^-][/tex]

[tex][OH^-]=10^{-3}M[/tex]

Thus the concentration of hydroxide ions is more than the concentration of hydrogen ions.

Answer:

12 atoms of hydrogen will be present in the product

Explanation:

12 atoms of hydrogen will be present in the product because the law of conservation of mass states that mass is neither created nor destroyed in chemical reactions.

The law of conservation states that the mass of the element remains the same during the course of the reaction.

The law of reaction conformed by the following:-  

According to the question, the amount of hydrogen is 12 atoms in the reactant and the amount will remain the same at the end of the reaction, which is a product that is 12 atoms

Hence, the amount remains the same in the reaction that is 12 atoms

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Answer:

the answer is d all of them are used

Answer:

all of them are correct types used/ mites

Explanation:

I did some research and apparently all of the above are types of insects used to determine time of death....but Im not 100% sure about mites( it Is said that they are used to provide forensically important information to estimate the post mortem interval, post berial interval, cause of death and relocation of dead body).

i hope this helps

Answer:

Gas

Explanation:

I dunno but a lucky guess i guess

No they are not, as climate is long term conditions for an area while weather is temporary

the answer for this question is Mister

Answer:

Explanation:

All compounds are molecules, but not all molecules are compounds. That is because a molecule can be made up of two atoms of the same kind, as when two oxygen atoms bind together to make an oxygen molecule. However, all compounds are made up of two or more different types of atoms.

Answer:

the last one

Explanation:

Answer:

Water is unique because of our need to survive on something so simple. It is just 2 hydrogen atoms and an oxygen. so simple, but necessary for all of our lives. Just 3-4 minutes without it causes permanent damage

I uploaded the answer to a file hosting. Here's link:

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Answer:

3.0x10¹⁹ atoms

Explanation:

First we convert 10 mg of mercury into grams:

Then we convert 0.01 g of mercury into moles, using its molar mass:

Then we convert moles into number of atoms, using Avogadro's number:

Answer:

chlorate changes to chlorous acid

Answer:

a. Ca(OH)₂ = 74.08 g/mol

b. H₂O₂ = 34 g/mol

c. KCl = 74.55 g/mol

d. NaH₂PO₄  = 119.97 g/mol

Explanation:

In order to determine the molar mass of each compound we need to sum, the molar mass of each element.

a. Ca(OH)₂

40.08 g/mol (Ca) + 2 . 16 g/mol (O) + 2 . 1 g/mol (H) = 74.08 g/mol

b. H₂O₂ → 2 . 1 g/mol (H) + 2 . 16 g/mol (O) = 34 g/mol

c. KCl → 39.1 g/mol (K) + 35.45 g/mol (Cl) = 74.55 g/mol

d. NaH₂PO₄

23 g/mol (Na) + 2 . 1 g/mol (H) + 30.97 g/mol (P) + 4 . 16 g/mol (O) = 119.97 g/mol

Answer:

[tex]3 g/cm^{3}[/tex]

Explanation:

Density is a measure of a substance's mass over its volume.

d = m/v

Therefore d = 60g/20cm3 = 3 g/cm3

Answer:

Answer:

see explanation and punch in the numbers yourself ( will be better for your test)

Explanation:

If you are given atoms you need to divide by Avogadro's number 6.022x10^23

then you will have moles of sulfur-- once you have moles multiply by the molar mass of sulfur to go from moles to grams

mm of sulfur is 32 g/mol

Mole measure the number of elementary entities of a given substance that are present in a given sample. Therefore, 15.6 is the mass in gram of 8.42 x 10²² atoms of sulfur.

The SI unit of amount of substance in chemistry is mole. The mole is used to measure the quantity of amount of substance. It measure the number of elementary entities of a given substance that are present in a given sample. There are so many formula for calculating mole.

we know one mole of any element contains 6.022×10²³ atoms which is also called Avogadro number

mole of sulfur =given number of atoms of sulfur ÷ 6.022×10²³(Avogadro number)

given number of atoms of sulfur= 8.42 x 10²²

Substituting the values

mole of sulfur=8.42 x 10²²÷ 6.022×10²³

mole of sulfur = 0.49moles of sulfur

mass of sulfur= moles of sulfur× Molar mass of sulfur

mass of sulfur=15.6gram

Therefore, 15.6 is the mass in gram of 8.42 x 10²² atoms of sulfur.

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Answer:

I think 6 miles

Explanation:

6 miles is larger than 30,000 feet.

To compare the sizes of 6 miles and 30,000 feet, we need to convert one of the measurements to the same unit as the other. Since both miles and feet are units of length, we can convert one to the other.

1 mile is equal to 5,280 feet. Therefore, to convert 6 miles to feet, we multiply by the conversion factor:

6 miles × 5,280 feet/mile = 31,680 feet

Now we can compare 31,680 feet to 30,000 feet. Since 31,680 feet is larger than 30,000 feet.

Hence, we can conclude that 6 miles is larger than 30,000 feet.

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Answer: in a straight path!

Explanation: hope this helps

Answer:

Atmoshphere!

Explanation:

I took the test and got a 100%! :) Hope this helps, plz mark brainliest!

Answer:

Minerals can form in three primary ways being precipitation, crystallization from a magma and solid- state transformation by chemical reactions (metamorphism). Mineral Precipitation is when a mineral is formed by crystallization from a solution. Examples include quartz, halite (table salt), calcite, and gypsum.

Answer:

When magma cools slowly, deep below the surface, it has time to form large crystals in regular patterns. The second way that minerals form is through solutions. (A solution is when one substance is dissolved uniformly in a liquid.) When elements and compounds leave the solution, they can crystalize.

Answer:

0.112M is molarity of the Na₂S₂O₃ solution

Explanation:

First, the KIO₃ reacts with KI as follows:

KIO3 (aq) + 5 KI (aq) + 6 HCl (aq) → 3 I2 (s) + 6 KCl (aq) + 3 H2O (l)

Then, the I₂ produced reacts with the Na₂S₂O₃ as follows:

2 Na2S2O3 + I2 → Na2S4O6 + 2 NaI

Thus, to solve this question, we need to obtain the moles of KIO₃ that react, then, the moles of I₂ produced -Using the chemical reaction- to find the initial moles of Na₂S₂O₃. With these moles and the volume we can find molarity of the solution:

Moles KIO₃:

21.45mL = 0.02145L * (0.0135mol/L) = 2.896x10⁻⁴ moles KIO₃

Moles I₂:

2.896x10⁻⁴ moles KIO₃ * (3mol I₂ / 1mol KIO₃) = 8.687x10⁻⁴ moles I₂

Moles Na₂S₂O₃:

8.687x10⁻⁴ moles I₂ * (2mol Na₂S₂O₃ / 1mol I₂) = 1.737x10⁻³ moles Na₂S₂O₃

As the volume of the titrated solution is 15.55mL, molarity is:

1.737x10⁻³ moles Na₂S₂O₃ / 0.01555L =

Answer:

Number of moles: 0.07407407407

Answer:

There are six liquid elements present in the periodic table. They are bromine,mercury ,caesium,gallium,rubidium and francium.

The metalloids; boron (B), silicon (Si), germanium (Ge), arsenic (As), antimony (Sb), tellurium (Te), polonium (Po) and astatine (At) are the elements found along the step like line between metals and non-metals of the periodic table.

The gaseous element group; hydrogen (H), nitogen (N), oxygen (O), fluorine (F), chlorine (Cl) and noble gases helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), radon (Rn) are gases at standard temperature and pressure (STP).

Explanation: