Anyone know how to do this please!! ? I will mark brainlist

Answer:

KOH  molar mass = 39 + 16 + 1 = 56g

To make 1 L of 1M soln needs 56g KOH

To make 500mL 1M needs 56/2 = 28g

To make 500mL 0.2M needs 28 x 0.2gn:

Answer:

Volume occupied by 55.5 moles of water gas at STP = 1240 Liters.

Explanation:

1st keep in mind that 'volume' in the context of problems like this apply only to the gas phase form of the substance. Water in solid form (ice) or liquid form (liquid water) do not apply. Volume in this case is referred to as 'molar volume' and is a gas occupying 22.4 liters at STP conditions (0°C, 1Atm).

So, if 1 molar volume of water gas (steam) occupies 22.4 Liters at STP, then 55.5 moles of water gas occupies 22.4 Liters/mole x 55.5 moles = 1243.2 Liters, or 1240 Liters (3 sig. figs.).   :-)

Answer: "In 1913 he used self-built equipment to prove that every element's identity is uniquely determined by the number of protons it has."

Explanation: If you are using this in an essay, use your own words when you use this. I got this from a website. But I hope it helps!

Answer:

  2AlBr₃  +  3K₂SO₄ →   6KBr  +  Al₂(SO₄)₃

Explanation:

Given species;

  Reactants

    Aluminum bromide  = AlBr₃

    Potassium sulfate = K₂SO₄

Products

    Potassium bromide  = KBr

    Aluminum sulfate = Al₂(SO₄)₃

 So, the reaction equation is given as:

          AlBr₃  +  K₂SO₄ →   KBr  + Al₂(SO₄)₃

To balance this chemical equation, let us an algebraic approach;

        aAlBr₃  +  bK₂SO₄ →   cKBr  +  dAl₂(SO₄)₃

Conserving Al;

        a  = 2d

   Conserving Br;

        3a  = c

   Conserving K;

       2b  = c

     Conserving S;

       b  = 3d

     Conserving O;

      4b  = 12d

    if a  = 1;

        c = 3

       b = [tex]\frac{3}{2}[/tex]

        d  = [tex]\frac{1}{2}[/tex]  

 Now, multiply through by 2;

  a  = 2, b  = 3, c = 6 and d = 1

      2AlBr₃  +  3K₂SO₄ →   6KBr  +  Al₂(SO₄)₃

Answer:

The effective number of bonds in sulfate ion is 1.5

Explanation:

The number of chemical bonds between two atoms is known as the bond order.

In covalent bonds between two atoms, a single bond has a bond order of one, a double bond has a bond order of two, a triple bond has a bond order of three.

If there are more than two atoms in a molecule, the effective number of bonds can be determined by applying the following steps:

1. Draw the Lewis structure.

2. Count the total number of bonds.

3. Count the number of bond groups between individual atoms.

4. Divide the number of bonds between atoms by the total number of bond groups in the molecule.

For the sulfate ion, the resonance structure is shown in the attachment below. From the structure;

Total number of bonds = (2 × 2) + (2 × 1) = 6

Total number of bond groups = 4

Effective number of bonds = 6/4 = 1.5

Therefore, the effective number of bonds in sulfate ion is 1.5

Answer:

mass

Explanation:

Answer:

Diagram 1

Explanation:

The solubility of the oxygen gas in water has to do with the interaction of the oxygen with the dipoles in water.

Water is a polar molecule having oxygen as the negative dipole and hydrogen as the positive dipole.

Water can interact with the oxygen atoms in the molecule via intermolecular hydrogen bonds with molecular oxygen as shown in diagram 1.

Answer:

Substance B

Explanation:

Molar heat of A = 31.2J/mole.°C

Molar heat of B =  11.2 J/mole∙°C.

The molar heat of a substance is the amount of heat that must be added to a mole of a substance to raise the temperature by 1°C.

Answer:

B. a nuclear reactor core (1000°C)......

Answer:

FALSE

they're called transition metals

Answer:

false

Explanation:

The 38 elements in groups 3 through 12 of the periodic table are called "transition metals." As with all metals, the transition elements are both ductile and malleable, and conduct electricity and heat.

Answer:

a. W = 5,708 J, Q = 5,708 J, ΔU = 0 and ΔH = 0.

b. 2,231 J.

Explanation:

Hello!

a. In this case, since this is an isothermal process (constant temperature) it is possible to infer that the work is computed as shown below:

[tex]W=nRTln(\frac{p_1}{p_2} )=1mol*8.314\frac{J}{mol*K}*298.15Kln(\frac{10.bar}{1.0bar} )\\\\W=5708J[/tex]

Now, since this is an isothermal process we know by definition ΔU = 0 and ΔH = 0, therefore the involved heat is:

[tex]Q-W=0\\\\Q=W=5708J[/tex]

b. In this case, since the process is isobaric but goes to the same final volume in part a, we can compute the initial and final volume based on the part a's conditions by using the ideal gas equation:

[tex]V_1=\frac{nRT}{p_1} =\frac{1mol*0.083145\frac{*L}{mol*K}*298.15K}{10.bar} =2.48L\\\\V_2=\frac{nRT}{p_2} =\frac{1mol*0.083145\frac{*L}{mol*K}*298.15K}{1.bar} =24.8L[/tex]

Thus, the work done here is:

[tex]W=p(V_2-V_1)=1bar(24.8L-2.48L)=22.3bar*L*\frac{1x10^5Pa}{1bar} *\frac{1m^3}{1000L} \\\\W=2231J[/tex]

Best regards!

Okay I need an explanation from YOU. when is this due? If it’s last minute, why didn’t you do it when you had time? This is very irresponsible, unless you have a personal reason. Please quit commenting on others just for the points. I helped you with one, because I thought it was just one question you needed help with. No one is going to finish this for you. I’m sorry but it’s the truth, everyone here needs help. No one is here TO help. So please be cooperative and try to learn. Of course, I’m sorry if it is for a very personal reason as it happens to everyone where you need the work ASAP because of a reason. Hopefully, it’s not because you were lazy. Appreciate your education as not many people in the world have it.

Answer:

Explanation:

Li+H2O..................LiOH+H2

mass of Li=17.8 g

No of moles of Li=17.8/7=2.5

mass of H2O=50.0 g

No of moles of H2O=50.0/18=2.8

limiting reagent is Li so 1 mole of Li produce 1 mole of LiOH therefore 2.5 mole of Li produce 2.5 moles of LiOH now we have to convert it into grams

moles=given mass/molar mass

given mass=moles*molar mass

molar mass of LiOH=24

mass=2.5*24=60 gram

Answer:

2.445 g

Explanation:

Step 1: Given and required data

Step 2: Calculate the mass of water

We will use the following expression.

Q = ∆H°vap × m

m = Q / ∆H°vap

m = 5525 J / (2260 J/g)

m = 2.445 g

Answer:

0.4

Explanation:

Given parameters:

Mass of NaCl  = 0.564g

Mass of KCl  = 1.52g

Mass of LiCl = 0.857g

Unknown:

Mole fraction of KCl = ?

Solution:

First, find the number of moles of the given species;

     Number of moles  = [tex]\frac{mass}{molar mass}[/tex]

Molar mass of KCl  = 39 + 35.5 = 74.5g/mol

Molar mass of NaCl  = 23 + 35.5 = 58.5g/mol

Molar mass of LiCl  =  7 + 35.5  = 42.5g/mol

  Number of moles of KCl  = [tex]\frac{1.52}{74.5}[/tex]   = 0.02mol

  Number of moles of NaCl  = [tex]\frac{0.564}{58.5}[/tex]   = 0.0096mol

  Number of moles of LiCl  = [tex]\frac{0.857}{42.5}[/tex]   = 0.02mol

Sum of moles  = 0.02mol + 0.0096mol + 0.02mol  = 0.0496mol  

Mole fraction of KCl  = [tex]\frac{0.02}{0.0496}[/tex]   = 0.4

Answer:

.4

Explanation:

Answer:

A : convection

B : conduction

Explanation:

Answer:

A. Convection

B. Conduction

Explanation:

Answer:

Take in carbon dioxide, reduces water loss, and produce oxygen.

Explanation: Hi! I've learned about these things in the past, really tough stuff! Hopefully this helps, I believe the three options above are correct, only one I'm possibly questioning is producing oxygen. Good luck!

Answer:

Take in carbon dioxide, reduces water loss

Explanation:

Answer:

Wave Frequency

Answer:

oop whats dis

Explanation:

Answer:

[KHP] = 0.0428M

Explanation:

2 methods to calculate concentration after dilution

1. Use dilution equation

Molarity of concentrate (M₁) x Volume of Concentrate (V₁)

           =    Molarity of dilute (M₂) x Volume of dilute (V₂)

M₁ x V₁ = M₂ x V₂ => M₂ = M₁ x V₁ / V₂ = (1.07M)(10ml)/(250ml) = 0.0428M

2. Concentration Equation

moles KHPh = Molarity (M)  x  Volume (V) = 1.07M x 0.010L =0.0107 moles KHP

Concentration KHP = moles solute / volume of solution in Liters

= 0.0107 moles KHP / 0.25L = 0.0428M

The molarity of 10.00 mL sample of a 1.07 M solution of potassium hydrogen phthalate diluted to 250.0mL is 0.0428M.

HOW TO CALCULATE MOLARITY:

C1V1 = C2V2

Where;

According to this question,

Learn more about how to calculate molarity of a solution at: https://brainly.com/question/13386686?referrer=searchResults

Answer:

A

Explanation:

A p e x

We are given:

Mass of solvent (water) = 100 grams

Mass of solute (NaCl) = 20 grams

Mass of the Solution:

Mass of Solution = Mass of Solute + mass of Solvent

100 + 20 = 120 grams

Mass Percent of NaCl:

We know that

mass percent of NaCl = (Mass of NaCl / Mass of Solution) * 100

replacing the variables

Mass% of NaCl = (20 / 120)*100

Mass% of NaCl = 100 / 6

Mass% of NaCl = 16.67%

Answer:

64.4g

Explanation:

The chemical reaction that will produce HNO₃ from NO₂ is given below:

        3NO₂  +  H₂O →  2HNO₃  + NO

Given;

Mass of HNO₃  = 88g

  Now;

To solve this problem, find the number of moles of HNO₃;

  Number of moles  = [tex]\frac{mass}{molar mass}[/tex]  

      Molar mass of HNO₃ = 1 + 14 + 3(16) = 63g/mol

 Number of moles  = [tex]\frac{88}{63}[/tex]   = 1.40mol

From the balanced reaction;

    2 mole of HNO₃ is produced from 3 mole of NO₂

   1.4 mole of HNO₃ will be produced from [tex]\frac{1.4 x 3} {2}[/tex]   = 2.1mole of NO₂  

Mass of NO₂ = number of moles x molar mass

  Molar mass of NO₂ = 14 + 2(16) = 46g/mol

  Mass of NO₂ = 1.4 x 46  = 64.4g

Answer

When magma reaches the surface it is called lava. After lava has cooled it forms solid rock.

Answer:

Volcano

Explanation:

when magma reaches the surface it cools and then magma  will start coming out over and over and over again. Then we have a volcano. hopemthis helps

Answer:

b. 51.63%

Explanation:

Step 1: Given data

Step 2: Calculate the mass corresponding to 7.35 × 10⁻³ moles of oxalate

The molar mass of C₂O₄²⁻ is 88.02 g/mol.

7.35 × 10⁻³ mol × 88.02 g/mol = 0.647 g

Step 3: Calculate the mass percent of oxalate in the sample

% w/w = mass of oxalate / mass of the sample × 100%

% w/w = 0.647 g / 1.253 g × 100%

% w/w = 51.63%

Answer:

0.065M

Explanation:

The reaction expression is given as:

         HCl   +   KOH  →  KCl + H₂O

Given parameters:

Volume of KOH  = 25.81mL  = 0.02581L

Molarity of KOH = 0.125M

Volume of HCl  = 50mL  = 0.05L

Unknown:

Molarity of the acid  = ?

Solution:

To find the molarity of the acid, HCl, let us use the mole concept.

  First, find the number of moles of the base, KOH;

Number of moles of KOH = molarity of KOH x volume of KOH

   Number of moles of KOH  = 0.125 x 0.0258 = 0.003225mol

From the balanced reaction equation:

   1 mole of KOH reacted with 1 mole of HCl

   0.003225mol of KOH will react with 0.003255mole of HCl

Molarity of HCl  = [tex]\frac{number of moles of HCl}{Volume of HCl}[/tex]

Molarity of HCl  = [tex]\frac{0.003255}{0.05}[/tex]   = 0.065M

Answer:

Hydrogen sulfide reacts with aqueous selenous acid to produce selenium disulfide:

H2SeO3 + 2 H2S → SeS2 + 3 H2O

Selenium disulfide consists of 8-membered rings. It has an approximate composition of SeS2, with individual rings varying in composition, such as Se4S4 and Se2S6. Selenium disulfide has been used in shampoo as an antidandruff agent, an inhibitor in polymer chemistry, a glass dye, and a reducing agent in fireworks.[15]

Selenium trioxide may be synthesized by dehydrating selenic acid, H2SeO4, which is itself produced by the oxidation of selenium dioxide with hydrogen peroxide:[17]

SeO2 + H2O2 → H2SeO4

Hot, concentrated selenic acid can react with gold to form gold(III) selenate.[18]

Answer:

[tex]PO_4^{3-}(aq)+3Ag^+(aq)\rightarrow Ag_3PO_4(s)[/tex]

Explanation:

Hello!

In this case, since the net ionic equation of a chemical reaction shows up the ionic species that result from the simplification of the spectator ions, which are those at both reactants and products sides, we take into account that aqueous species ionize into ions whereas liquid, solid and gas species remain unionized. In such a way, for the reaction of cesium phosphate and silver nitrate we can write the complete molecular equation:

[tex]Cs_3PO_4(aq)+3AgNO_3(aq)\rightarrow Ag_3PO_4(s)+3CsNO_3(aq)[/tex]

Whereas the three aqueous salts are ionized in order to write the following complete ionic equation:

[tex]3Cs^+(aq)+PO_4^{3-}(aq)+3Ag^+(aq)+3NO_3^-(aq)\rightarrow Ag_3PO_4(s)+3Cs^+(aq)+3NO_3^-(aq)[/tex]

In such a way, since the cesium and nitrate ions are the spectator ions because of the aforementioned, the net ionic equation turns out:

[tex]PO_4^{3-}(aq)+3Ag^+(aq)\rightarrow Ag_3PO_4(s)[/tex]

Best regards!