hello! could anyone help me? i don't really understand. Thank you!! ​

Answer:

5.185 gcm⁻³

Explanation:

The formula to find density is:

Density = [tex]\frac{mass}{volume}[/tex]

Density = [tex]\frac{42}{8.1}[/tex]

Density of magnetite sample = 5.185 gcm⁻³

Answer: 5.185

Explanation: the formula to find the density is

Density = mass/volume

Density = 42/8.1

Density of magnetite sample = 5.185 g/cm3

Answer:

5.50 moles of magnesium oxide is 221.6742 grams

Explanation:

to do this you multiply the number of moles by the molar mass

Answer:

Al + S -> Al2S3

Al and S are the reactants, Al2S3 is the product

Explanation:

0.634 mol of NaOH can 200 mL of this buffer neutralize before the pH rises by 0.50.

A buffer is a solution that can resist pH change upon the addition of an acidic or basic components.

Solution:

A buffer consists of 0.11 M HA and 0.11 M NaA.

Ka =[tex]4.82 X 10^-^5[/tex]

pKa = -log ([tex]4.82 X 10^-^5[/tex])

pKa = 11.83

Using Henderson equation to calculate pH of the buffer solution.

pH =PKa -log [tex]\frac{Conjugate \;base}{Acid}[/tex]

pH = 11.83 - [tex]\frac{0.11 M}{0.11 M}[/tex]

pH = 10.83

pOH = 14 - 10.83

pOH = 3.17

Calculating the moles of NaOH added by the addition of 200 mL

Molarity = [tex]\frac{Moles \;of \;NaOH}{0.2 L}[/tex]

3.17 X 0.2 = Moles of NaOH

Moles of NaOH = 0.634 mol

Hence, 0.634 mol of NaOH can 200 mL of this buffer neutralize.

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The average temperature during the ice age was around 46 degrees Fahrenheit although the polar regions were far colder, around 25 degrees Fahrenheit which is colder than the global average.

The monthly mean temperature: It is calculated by adding the daily mean temperatures for each day of the month and dividing the total by the number of days in a month.

The average global temperature during the period known as the Last Glacial Maximum from roughly 23,000 to 19,000 years ago was about 46 degrees Fahrenheit (7.8 degrees Celsius), some 13 degrees Fahrenheit (7 Celsius) colder than 2019, the researchers said.

A team of scientists has nailed down the temperature at the peak of the last ice age, a time known as the ast Glacial Maximum, to about 46 degrees Fahrenheit.

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Answer: below

Explanation:

Glass can be heated up and turn into a liquid, its a hard procces, due to the extreme heat, machines are used today.

Answer:

answer

[tex]\huge\tt{\underline{\colorbox{maroon}{✨ANSWER}}}[/tex]

Explanation:

Because glass is hard, it must be a supercooled liquid. Glass, however, is actually neither a liquid—supercooled or otherwise—nor a solid. It is an amorphous solid—a state somewhere between those two states of matter

The term pH has to do with the hydrogen ion concentration of a solution.

The term pH has to do with the hydrogen ion concentration of a solution. Let us now proceed the pH of the solutions;

a) pH of HCl = -log(0.25) = 0.62

b) pH of H2SO4 = -log(0.15) = 0.82

c)  We have to set up an ICE table here;

              C6H5COOH + H2O ⇄ C6H5COO- + H^+

I            0.15                                  0                      0

C          -x                                       +x                     +x

E         0.15 -x                                  x                      x

Ka = [C6H5COO-] [ H^+]/[C6H5COOH]

6.4 x 10^-5 = x^2/0.15 - x  

6.4 x 10^-5(0.15 - x) = x^2

9.6 * 10^-6 - 6.4 x 10^-5x = x^2

x^2 + 6.4 x 10^-5x - 9.6 * 10^-6 = 0

x=0.003 M

Hence;

[C6H5COO-] = [ H^+] = x = 0.003 M

pH = - log[0.003 M] = 2.5

d) [OH-] [H^+] = 1.0 x 10-14 mol2 dm-6

[H^+] = 1.0 x 10-14 mol2 dm-6/ 0.10 mol dm-3

[H^+] = 1 * 10^-13 M

pH= - log[1 * 10^-13 M] = 13

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Answer:

.006L or 6 mL

Explanation:

Answer:

261.1 N

Explanation:

Force = mass × acceleration due to gravity

Force is also known as weight. So:

Weight = 70 × 3.73 = 261.1 N

Answer:

if you meant CH3-CH=CH-CH3, the IUPAC name is 2-butene.

Answer:

[A] Melting

Explanation:

From the giving it means:

H2O(s) - Solid  {Ice}

H2O(l) - Liquid   {water}

So the equation is:

Liquid ⇒ Solid + Heat

Water ⇒ Ice + Heat

Hence, if you add ice and heat it equal to melting.

Therefore the correct answer is [A] Melting.

Kavinsky

Answer: C. Freezing

Explanation:

Answer:

Air pollution affects the compounds in the air, causing heat to change dramatically over time in the atmosphere.

Answer:

.455 M

Explanation:

Ba (OH)^2   has mole weight of (from periodic table) = 171.341 gm/mole

49.2 gm  / 171.341  gm/mole = .287 mole

.287 M / .62984 L  = .455 M

Answer:

A

Explanation:

Increasing the the temperature would favour the endothermic reaction which is the forward direction however increasing the pressure would make the reaction try to counteract this change by favouring the reaction that would create more products so the equilibrium will shift left instead of right.

Hope this helps.

Answer:

Is this math? Cause as a fourth grader, I can do Algebra, but not this.

Explanation:

Answer:

Electrovalent.

Explanation:

[tex]\text{The element P is }~ _{12}Mg\\\\\text{The element Q is }~ _{17}Cl\\\\\text{The chemical bond between P and Q is ionic or electrovalent bond.}\\\\Mg^{2+} + 2\text{Cl}^{-} \rightleftharpoons MgCl_2[/tex]

Answer: 63.9

Explanation:

Answer:

wilt

Explanation:

Without sunlight, photosynthesis cannot occur, and photosynthesis makes chlorophyll, the plant's food. Therefore, a plant without sunlight will "starve," and begin wilting.

Answer:

it will true

Explanation:

Answer:

Probably stop taking the prescribed durg and contact your pharmacist and your doctor that gave you your prescription asap.

Explanation:

Both of those health professionals will assist the patient in understanding how to go about the next steps for side effect relief.

Answer:

0.25m/s²

Explanation:

here

weight(w)-20 N

mass(m)-5 kg

acceleration (g) -?

we know

w=mg

g=m/w

=5/20

=0.25 m/s²

Answer:

acceleration=0.04g/s

Explanation:

force=Ma

20N=5kgXa

5kg=5000g

20N=5000Xa

20N=5000a

divide both sides by 5000

acceleration=0.04g/s

Answer:

Step 1: Write the balanced chemical equation with the states first:

Ca(OH)₂ (aq) + 2NH₄Cl (aq) → CaCl₂ (aq) + 2NH₃ (g) + 2H₂O (l)

Step2: Write the complete ionic equation, break only the aqueous ones only :

Ca²⁺ + 2OH⁻ + 2NH₄⁺ + 2Cl⁻ → Ca⁺² + 2Cl⁻ + 2NH₃ (g) + 2H₂O (l)

Step 3: cancel the spectator ions ( the ions which stay the same like calciumn and chlorine ions here)

almost the same

just different in bond

pick one volume and concentration as a sample

5.9 ml + 28.752 ml = 34.652

M1V1=M2V2

0.56 x 28.752 = M2 x 34.652

M2=0.464 M

The answer is  moving left to right across a period the nucleus has a greater pull on the outer electrons and the atomic radii decreases.

The atomic number or nuclear charge number (symbol Z) of a chemical element is the charge number of an atomic nucleus.

Atomic Number (generally ) =  Number of Protons

The atomic number can be used to uniquely identify ordinary chemical elements.

In an ordinary uncharged atom, the atomic number is also equal to the number of electrons.

The atomic number increases moving left to right across a period and subsequently so does the effective nuclear charge.

Therefore, moving left to right across a period the nucleus has a greater pull on the outer electrons and the atomic radii decreases.

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Answer:

the United States and the Soviet Union.

Explanation:

Basically we were in toe to toe with the russians for space explorations like who's gonna get to space first or moon or do such explorations