1) Consider this row in the periodic table. What changes can you predict based on what information is provided by the boxes for each element?

A) The elements change from solids to gases and the valence electrons decrease in number.

B) As you move across the row, the number of electrons increases and reactivity also increases.

C) They have different atomic numbers and mass numbers; they have the same number of valence electrons.

D) Both the atomic numbers and the mass numbers increase; the least reactive element is in the last box.

USA test prep question

Question 1

[tex]\text{pH}=-\log(\text{H}^{+})\\\\13=-\log(\text{H}^{+})\\ \\ \text{[H}^{+}]}=1 \times \boxed{10^{-13} \text{ moles per liter}} \\ \\ \text{[H}^{+}] \times \text{[OH}^{-}] =1 \times 10^{-14} \text{ M}\\\\\text{[OH}^{-}]=\boxed{1 \times 10^{-1} \text{ moles per liter}}[/tex]

Question 2

[tex]\text{pH}=-\log(\text{H}^{+})\\\\\text{pH}=-\log(1.0 \times 10^{-4})=\boxed{4}[/tex]

Answer:

Molecular compounds are inorganic compounds that take the form of discrete molecules. Examples include such familiar substances as water (H2O) and carbon dioxide (CO2). These compounds are very different from ionic compounds like sodium chloride (NaCl).

Answer:

5.96 * 10^23 molecules

Explanation:

Don't start counting up the number of CsHsNs and Os there are Counting up the atom ions will get a wrong answer.  The question is asking for the number of molecules. That means you do not break down each molecule to  find the number of molecules. You modify 1 mol to find out how many molecules are in 0.99 mols. Do that using a proportion.

1 mol contains 6.01 * 10^23 molecules

0.99 mol contains x

1/0.99 = 6.02 * 10^23 / x molecules

x = 0.99 * 6.02 * 10^23

x = 5.96 * 10^23

Explanation:

I) carbon dioxide

ii) nitrogen dioxide

iii) nitric acid

iv) sulphric acid

v) Potassium dichromate

vi) hexacyanoferrate (III) ion( not sure)

Answer:

3.82 x 10²¹ molecules As₂O₃

Explanation:

To find the amount of molecules arsenic (III) oxide (As₂O₃), you need to (1) convert kg to lbs, then (2) convert g As₂O₃ to moles As₂O₃ (via molar mass), and then (3) convert moles to molecules (via Avogadro's number).

1 kilogram = 2.2 lb

Molar Mass (As₂O₃): 2(74.992 g/mol) + 3(15.998 g/mol)

Molar Mass (As₂O₃): 197.978 g/mol

Avogadro's Number:

6.022 x 10²³ molecules = 1 mole

0.0146 g As₂O₃            1 kg                  189 lb
------------------------  x  ---------------  x  ------------------  x   ................
         1 kg                     2.2 lb          

       1 mole                6.022 x 10²³ molecules
x  ------------------  x  ---------------------------------------  = 3.82 x 10²¹ molecules As₂O₃
      197.978 g                        1 mole

Answer:

2 Fe(HCO₃)₃ + 3 CaO ---> 1 Fe₂O₃ + 3 Ca(HCO₃)₂

Explanation:

The unbalanced equation:

Fe(HCO₃)₃ + CaO ---> Fe₂O₃ + Ca(HCO₃)₂

Reactants: 1 iron, 3 hydrogen, 3 carbon, 10 oxygen, 1 calcium

Products: 2 iron, 2 hydrogen, 2 carbon, 9 oxygen, 1 calcium

As you can see, the reaction is clearly unbalanced because the number of each element on both sides is different. The best way to go about balancing an equation is by trying to first balance an element located in only one molecule on either side. For example, I started trying to balance  iron. After balancing iron, I looked to balance other elements that would have been affected by the new coefficient (i.e., hydrogen, carbon).

The balanced equation:

2 Fe(HCO₃)₃ + 3 CaO ---> 1 Fe₂O₃ + 3 Ca(HCO₃)₂

Reactants: 2 iron, 6 hydrogen, 6 carbon, 21 oxygen, 3 calcium

Products: 2 iron, 6 hydrogen, 6 carbon, 21 oxygen, 3 calcium

Now, with these coefficients, the quantity of each element on both sides is the same.

Answer:

Explanation:

Mining:

    Mining is when certain substances are removed from the Earth, usually in large quantities. Mining can occur below the surface of the Earth via tunnels and caves. It can also occur at surface level through methods such as strip mining, which removes huge amounts of soil in the process

Answer:

55.5g of calcium chloride is produced in the reaction.

Explanation:

To calculate the amount of calcium chloride.

The reaction of calcium carbonate with hydrochloride acid gives calcium chloride

CaCO₃ +  2HCl  →  CaCl₂  + CO₂  +  H₂O

Mass of calcium carbonate (CaCO₃)= 50.0g

Molecular mass of CaCO₃ = Ca + C + O₃

                                             = 40+ 12 + 3(16) = 100g

No of moles of calcium carbonate CaCO₃ = given mass / molecular mass

                                                                          = 50g/ 100

                                                                            = 0.5 moles

Molecular mass of calcium chloride = 40+ 2(35.5)=(40+71.0)= 111g/mol

1 mole of calcium carbonate gives = 1 mole of calcium chloride

0.5 moles of calcium carbonate gives= 0.5 × 111g/mole

                                                                = 55.5g

To learn more about moles, grams and molecular mass, refer to-

https://brainly.com/question/11893320

#SPJ10

Answer:

A large absorption at 2950 cm⁻¹ indicates that there is likely an sp³C-H functional group somewhere in the molecule. The "sp³" designation means that this is a single bond because these atoms have 4 orbitals available (s + p + p + p) for hybridizing, meaning only single bonds are possible.

For a system PCl3(g) + Cl2(g) PCl5(g) at equilibrium at 25°C, for which H° = –92.5kJ at 25°C, the ratio of the partial pressure of PCl5 to the partial pressure of PCl3 is will increase

Generally, the equation for chemiecal reaction is mathematically given as

PC3 (g) + C₁₁₂ (g) = PC15 (g) 3

Assuming the addition of some Cl2 gas. The reaction will shift to the right at the invariant volume temperature, maintaining equilibrium. This results in a rise in P9Cl5(g) and a fall in PpCl3(g).

PpCl (g) /PpCl (g) will increase

Read more about Chemical Reaction

https://brainly.com/question/11231920

#SPJ1

The ratio of the partial pressure of PCl₅ to the partial pressure of PCl₃ is will increase for a system PCl₃ (g) + Cl₂ (g) --> PCl₅ (g) at equilibrium at 25°C, for which H° = –92.5kJ at 25°C when some Cl₂ (g) is added at constant volume and temperature.

Generally, the equation for chemical reaction is mathematically given as ;

PCl₃ (g) + Cl₂ (g) --> PCl₅ (g)

Assuming the addition of some Cl₂ gas,

The reaction will shift to the right at the constant volume and temperature, maintaining equilibrium.

This results in a rise in PCl₅ (g) and a fall in PCl₃(g).

Hence, the ratio of the partial pressure of PCl₅ to the partial pressure of PCl₃ is will increases

Read more about Chemical Reaction here;

brainly.com/question/11231920

#SPJ1

Answer:

Make life easy for your customers and they are more likely to come back and buy again.

Explanation:

For example, you have to hire the right talent. You don't want somebody on the job that doesn't know how to do anything.

The molecular weight of Cr3(AsO4)2 is 433.827.

Furthermore, the primary distinction between each is that molar mass gives the mass of a mole of a selected substance. While molecular weight is the mass of a molecule of a particular substance. At an equal time as the definition and devices are splendid for molar mass and molecular weight, the value is the same.

The sum of the atomic hundreds of all atoms in a molecule is based totally on a scale wherein the atomic loads of hydrogen, carbon, nitrogen, and oxygen are 1, 12, 14, and 16, respectively.

Learn more about molecular weight here https://brainly.com/question/26388921

#SPJ10

If data from a clinical trial contains personal information about a study participant, De-identification process should be used to separate identifying information from health information. Thus, Option (A) is correct

De-identification is a process of detecting identifiers (e.g., personal names and social security numbers) that directly or indirectly point to a person (or entity) and deleting those identifiers from the data.

De-identification and anonymization are strategies that are used to remove patient identifiers in electronic health record (EHR) data.

Hence, De-identification process should be used to separate identifying information from health information. Thus, Option (A) is correct.

learn More about health record here ;

https://brainly.com/question/11156017

#SPJ1

S=2, p=6, d=10, and f=14 the maximum number of electrons it can

accommodate.

The probability of finding an electron around the nucleus.

The principal number (n), is the number of the shell, it goes from 1 to 7 and is represented by the letter K, L, M, N, O, P, Q. The maximum number of electrons in the shells are, K = 2, L = 8, M = 18, N = 32, O = 32, P = 18, Q =8.

The secondary number (l) is the subshells, and it goes from 0 to 4 and is represented, in order, for the letter, s, p, d, f. The maximum number of electrons permitted in each subshell is s = 2, p = 6, d = 10, f = 14.

The magnetic number (ml), is represented by orbitals, and it goes from -l to +l, passing by 0. The maximum number of electrons is 2 for each one.

The spin number (ms) refers to the rotation of the electron, and it can be +1/2 or -1/2.

Hence, S=2, p=6, d=10, and f=14 the maximum number of electrons it can

accommodate.

Learn more about the orbitals here:

https://brainly.com/question/18914648

#SPJ1

Answer:

[Na]^+ [Cl]^-

Explanation:

Lets say its sodium, its number of electrons is 11, but when its stable (an ion), it is 10. and chloride, number of electrons is 17, but when its stable (an ion) it is 18. So the lewis structure for that is, remember with the straight brackets (not sure what it's called, but you know what I mean I guess) its this one: [ ]

Sodium will be + because it has more protons (11-10 = +1), and chloride will be - because it gained an electron, so has more electrons than protons (17-18 = -1)

So the lewis structure would be:

[Na]^+  for sodium

and

[Cl]^- for chlorine

Sodium chloride:

[Na]^+ [Cl]^-

Also just to add, only 1 of each atom (Na and Cl) was needed for the bonding, but if let's say example; 2 Cl was needed to bond with sodium, there would be 2 Cl (same) and 1 Na.

Answer:

=7.89013× 10^47 moles of zinc

Explanation:

1 atom contains 6.023×10^23 moles.

1.31×10^24 atoms of zinc contain6.023×10^24×1.31×10^.24

Answer:

OC. Fe³+

Explanation:

Greater reduction potential (bigger positive E value) means that things wants to get electrons. For this, you have to look at the chart that I have attached. Since, Fe3+ has highest E value out of other options, it will likely be reduced.

The species which is most likely to get reduced is Fe³⁺.

Reduction is the process of the addition of electrons and loss of oxygen atoms. It is part of redox reactions.

Redox reactions are the type of reactions in which oxidation and reduction simultaneously take place. Oxidation is the addition of oxygen atoms. Reduction is the removal of oxygen atoms.

Redox reaction can be represented as:

PbO (s) + H₂ (g) → Pb(s) + H₂O (l)

In the above reaction, PbO is getting reduced and H₂ is getting oxidized.

Fe³⁺ is most likely to get reduced because the more positive the value of reduction potential, the more will be its tendency to get reduced.

In the given four species, the value of the reduction potential of Fe³⁺ is the highest.

Values of the reduction potential of four species are:

Learn more about, redox reactions:

https://brainly.com/question/28300253

#SPJ7

Answer:

the cytoplasm

protein 3b more commonly called vpg

The concentration terms are molality, normality and mole fraction. Molarity can be used to find out the ionic strength of any solution. Therefore, 0.80g of Fe(NO[tex]_3[/tex])[tex]_3[/tex] are present in a 20.0 mL sample of a 0.500 M solution.

Molarity can be calculated by dividing number of moles of solute by volume of solution in litre. Molarity is affected by temperature. Its unit is mole/liter. It measure the concentration of any solute in a solution.

Mathematically,

Molarity= number of moles of solute/volume of solution in litre (1)

Where,

moles= given weight /by molecular weight

         = w/241.8

Substituting values in equation 1

0.500= (w/241.8)/(20.0 /1000)

w=0.80g

Therefore, 0.80g of Fe(NO[tex]_3[/tex])[tex]_3[/tex] are present in a 20.0 mL sample of a 0.500 M solution.

Learn more about Molarity, here:

https://brainly.com/question/16727614

#SPJ2

Answer:

To separate a metal from its ore using acid and preserving desirable products such as gold.

Explanation:

please make brainiest

Answer:

B

Explanation:

I took the test

Answer:

Large-scale insulin could be produced in relatively lesser time.

Explanation:

We already sort of do this where we infect the bacteria with a plasmid containing our insulin gene and it causes them to produce insulin. Since the question is saying that we edited their DNA directly, now these bacteria don't need to be infected with plasmid b/c now they can just pass these genes onto their offspring.

This will allow us to make TONS of insulin cuz bacteria are crazy good at making stuff and growing.

2 moles of ZnO are produced if 1 mole of Zn and 2 moles of [tex]O_2[/tex] is required.

A mole is defined as 6.02214076 × [tex]10^{23}[/tex] of some chemical unit, be it atoms, molecules, ions, or others. The mole is a convenient unit to use because of the great number of atoms, molecules, or others in any substance.

Balanced equation:

[tex]2 Zn + O_2[/tex] → [tex]2 ZnO[/tex]

For 2 moles of Zinc, we need 1 mol of Oxygen to produce 2 moles of Zinc oxide

For 1 mole Zn, we need 2 mol [tex]O_2[/tex] to produce 2 moles ZnO only.

Hence, 2 moles ZnO is produced.

Learn more about moles here:

https://brainly.com/question/8455949

#SPJ1

The percent yield would be 68.3%

This is given as:

Percent yield = yield/theoretical yield x 100%

From the equation:

[tex]2SO_2(g) + O_2(g) -- > 2SO_3(g)[/tex]

The mole ratio of the reactants is 2;1

Mole of 705 g SO2 = 705/64 = 11.02 moles

Mole of 80 g O2 = 80/32 = 2.5 moles

O2 is limiting.

Mole ratio of O2 and SO3 = 1:2

Mole equivalent of SO3 = 2.5 x 2 = 5.0 moles

Mass of 5 moles SO3 = 5 x 80 = 400 grams

Percent yield = 400/586 = 68.3%

More on percent yield can be found here: https://brainly.com/question/17042787

#SPJ1