How many grams are in 0.75 moles of zinc?

Answer:

The natural abundance of Re-185 is 40% and of Re-187 is 60%

Explanation:

Relative atomic mass is defined as the sum of the mass of each isotope times its relative abundances.

Is Rhenium has only 2 isotopes and the abundances are X and Y we can write:

X + Y = 1 (1)

And:

185X + 187Y = 186.2 (2)

Where X is abundance of Re-185 and Y abundance of Re-187

Replacing (1) in (2):

185X + 187(1-X) = 186.2

185X + 187-187X = 186.2

-2X = -0.8

X = 0.4 = 40%

And Y = 100% - 40% = 60%

Answer:

Over time, the Sun's differential rotation rates cause its magnetic field to become twisted and tangled. The "tangles" in the magnetic field lines can produce very, very strong localized magnetic fields. Places where "ropes" of bundled field lines "break" the surface of the Sun are active regions where sunspots form.

Answer:

reproduction and life are connected because when you reproduce you are creating life.

Answer:

C) 301.8

Explanation:

Hello!

In this case, since the solution is composed by water and salt, the total resulting mass comes up from adding the mixed mass of each one:

[tex]m_{sol}=m_{w}+m_{salt}[/tex]

Thus, we plug in to obtain:

[tex]m_{sol}=200.4g+101.42g\\\\m_{sol}=301.8g[/tex]

Therefore, the answer should be C) 301.8 as it has four significant figures.

Best regards!

Explanation:

The tendency of metals to lose electrons is a measure of their electropositivity or metallicity.

Electropositivity is a measure of the tendency of atoms of an element to lose electrons. It is closely related to ionization energy and electronegativity of an element.

Answer:

B,C,F

Explanation:

Answer:

b c f

Explanation:

Answer: B -2.37 -0.34

Explanation: A P E X

The redox reaction consists of the reduction and the oxidation halves and involves the transfer of electrons. The overall voltage for the Mg and Cu is 0.34 - (-2.37). Thus, option C is correct.

A nonspontaneous redox reaction is the loss and gain of the electrons when an external source of voltage is applied to initiate the electrochemical reaction.

The overall voltage of the redox reaction can be given by the oxidation and the reduction of half of the cell as,

Oxidation half: Mg(s) → Mg₂⁺ + 2e⁻  E° = -2.37 v

Reduction half: Cu₂⁺ + 2e⁻ → Cu(s)  E° = + 0.34 v

The overall voltage of the cell (E° cell) is calculated as,

E° cell = E°(reduction) - E°(oxidation)

= +0.34 - (-2.37)

= 2.71 v

Therefore, option C. 0.34 - (-2.37) is the overall voltage for the nonspontaneous redox reaction.

Learn more about redox reaction here:

https://brainly.com/question/14217644

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Your question is incomplete, but most probably your full question was, What is the overall voltage for a redox reaction with the half-reactions Mg(s) → Mg₂⁺ + 2e⁻ and Cu₂⁺ + 2e⁻ → Cu(s)?

A. -2.37 - 0.34

B. 0.34 - 2.37

C. 0.34 - (-2.37)

D. 2.37 - 0.34

Answer:

1000

Explanation:

Answer:

[tex]velocity = \frac{displacement}{time} \\ = \frac{5}{6} \\ velocity = \frac{5}{6} m {s}^{ - 1} [/tex]

The pH = 2.41

Given

5.0% by mass solution of acetic acid

the density of white  vinegar is 1.007 g/cm3

Required

pH

Solution

Molarity of solution :

[tex]\tt M=\dfrac{\%mass\times \rho\times 10}{MW~acetic~acid}\\\\M=\dfrac{5\times 1.007\times 10}{60}\\\\M=0.839[/tex]

Ka for acetic acid = 1.8 x 10⁻⁵

[H⁺] for weak acid :

[tex]\tt [H^+]=\sqrt{Ka.M}[/tex]

Input the value :

[tex]\tt [H^+]=\sqrt{1.8\times 10^{-5}\times 0.839}\\\\(H^+]=0.00388=3.88\times 10^{-3}\\\\pH=3-log~3.88=2.41[/tex]

White vinegar is a 5.0% by mass solution of acetic acid in water and if the density of white vinegar is 1.007 g/cm³ then the pH of solution is 4.8.

pH of any solution will be calculated as:

pH = - log[H⁺], where

[H⁺] = concentration of H⁺ ions

In this question we will calculate the concentration of H⁺ ions as:

[H⁺] = √Ka.M, where

Ka = acid dissociation constant for acetic acid = 1.8 x 10⁻⁵ (known)

M is molarity and this can be calculated as:

M = (% mass × density × 10) / Molar mass of acid

Given that,

% mass = 5.0% by mass solution of acetic acid

density = 1.007 g/cm³

Molar mass of acetic acid = 60

Now putting all these values on the above equation, we get

M = (5 × 1.007 × 10) / 60 = 0.839

Now, we calculate the concentration of H⁺ ions by putting values on that equation as:

[H⁺] = √(1.8 x 10⁻⁵)(0.839)

[H⁺] = 1.5 x 10⁻⁵

So, pH of the solution will be calculated as:

pH = -log(1.5 x 10⁻⁵)

pH = -(-4.8)

pH = 4.8

Hence, pH is 4.8.

To know more about pH, visit the below link:

https://brainly.com/question/10313314

Answer:

Exothermic

Explanation:

We as humans do not absorb heat. A good way to think about it is that when we workout we use energy from our body which causes our body temperature to rise. The energy used from food maintains our blood, respiration, and other systems in optimal condition. This requires energy from our body which ends up leaving the body as heat.

Answer:

You're answer is correct. The third answer is correct.

Explanation:

Producers have the most energy, since they gain energy directly from the sun. Their energy is then passed up this upside down pyramid, which the energy is decreased by about 10% each time.

#teamtrees #WAP (Water And Plant)

Answer:

Mass = 0.44 g

Explanation:

Given data:

Mass of vanadium =  ?

Number of atoms of vanadium = 5.2 × 10²¹ atoms

Solution:

It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance.

The number 6.022 × 10²³ is called Avogadro number.

1 mole = 6.022 × 10²³ atoms

5.2 × 10²¹ atoms ×  1mol / 6.022 × 10²³ atoms

0.86× 10⁻²  mol

0.0086 mol

Mass of vanadium:

Mass =  number of moles × molar mass

Mass = 0.0086 mol × 50.9 g/mol

Mass = 0.44 g

Answer:

In an exothermic reaction, the products are at a lower energy than the reactants. The difference between the energy of the reactants and the energy of the products is called the enthalpy change (∆H) of the reaction. For an exothermic reaction, the enthalpy change is always negative.

Answer: ENERGY: A food chain is a linear sequence of organisms through which nutrients and energy pass as one organism eats another; the levels in the food chain are producers, primary consumers, higher-level consumers, and finally decomposers. These levels are used to describe ecosystem structure and dynamics.

MATTER: When one organism eats another, the matter, or carbon, nitrogen, and other essential elements, are transferred from one to the other. These elements move from the producers, to the consumers, and eventually to the decomposers, cycling the matter through the ecosystem.

Explanation: look up

Answer:

Mass = 2.59 g

Explanation:

Given data:

Mass of AgS = 3.45 g

Mass of silver = ?

Solution:

Number of moles of AgS:

Number of moles = mass/molar mass

Number of moles = 3.45 g/ 139.93 g/mol

Number of moles = 0.024 mol

1 mole of AgS  contain 1 mole of Ag.

0.024 mol contain 0.024 mol of Ag.

Mass of silver:

Mass = number of moles × molar mass

Mass = 0.024 mol × 107.86 g/mol

Mass = 2.59 g

Answer:

i will tell your teacher that u uding online cheats to answer yout homeworks hhaahaha

Explanation:

good luck brooo hahahha

Answer:

OH⁻(aq) + H⁺(aq) ⇒ H₂O(l)

Explanation:

Let's consider the molecular equation that occurs when aqueous solutions of lithium hydroxide and hydrobromic acid undergo a neutralization reaction.

LiOH(aq) + HBr(aq) ⇒ LiBr(aq) + H₂O(l)

The complete ionic equation includes all the ions and the molecular species.

Li⁺(aq) + OH⁻(aq) + H⁺(aq) + Br⁻(aq) ⇒ Li⁺(aq) + Br⁻(aq) + H₂O(l)

The net ionic equation includes only the ions that participate in the reaction and the molecular species.

OH⁻(aq) + H⁺(aq) ⇒ H₂O(l)

Answer:1

Explanation: friction is showing us how in the past

Answer:

Explanation:

The answer is 32°F or 0° Celsius.

Hope it helped you.

Answer: 1) chemical change 2) chemical properties 3) ratio? 4) created nor destroyed

Explanation: 1) Matter is composed of exceedingly small particles called atoms. An atom is the smallest unit of an element that can participate in a chemical change. 2) A macroscopic sample of an element contains an incredibly large number of atoms, all of which have identical chemical properties. 3) A compound consists of atoms of two or more elements combined in a small, whole-number ratio. In a given compound, the numbers of atoms of each of its elements are always present in the same ratio. 4) Atoms are neither created nor destroyed during a chemical change, but are instead rearranged to yield substances that are different from those present before the change

Answer:

Potassium nitrate is a chemical compound with the chemical formula KNO3. It is an ionic salt of potassium ions K+ and nitrate ions NO3−, and is therefore an alkali metal nitrate. It occurs in nature as a mineral, niter (or nitre in the UK). It is a source of nitrogen, and nitrogen was named after niter.

Explanation:

Explanation:

Galileo found Venus went through the entire phase cycle, proving that she revolved completely around the Sun, as predicted by Copernicus in his heliocentric model. ... The phases of Venus could not be explained by Ptolemy's Geocentric Model. Galileo knew that the Roman Catholic Church was incorrect.

Answer:

The periodic table of elements puts all the known elements into groups with similar properties. This makes it an important tool for chemists, nanotechnologists, and other scientists. If you get to understand the periodic table and learn to use it, you'll be able to predict how chemicals will behave.

Answer:

Okayy

Explanation:

The periodic table arranges the chemical elements

All the members of a family of elements have the same number of valence electrons and similar chemical properties. The horizontal rows on the periodic table are called periods

It have many properties. Each column is called a group.

ALSO Metals are placed on the left-hand side of the periodic table , and non-metals on the right.

Metalloids can also be called semimetals. On the periodic table, the elements colored yellow, which generally border the stair-step line, are considered to be metalloids.

Answer:

Chlorine gas.

Explanation:

Hello!

In this case, the undergoing chemical reaction is:

[tex]2Na+Cl_2\rightarrow 2NaCl[/tex]

Thus, given the moles of reacting both sodium and chlorine, we compute the moles of sodium chloride yielded by each reactant by considering the 2:2 and 1:2 mole ratios:

[tex]n_{NaCl}^{by\ Na}=6.70molNa*\frac{2molNaCl}{2molNa}=6.70molNaCl \\\\n_{NaCl}^{by\ Cl_2}=3.20molCl_2*\frac{2molNaCl}{1molCl_2}=6.40molNaCl[/tex]

Thus, since chlorine yields less moles of sodium chloride, we infer it is the limiting reactant.

Best regards!

Answer:

Na(s) + H₂O (l) → NaOH(aq) + H₂(g).

Explanation:

answer is this thank you I hope it helps you pls like