If you know about crystals can you tell me if this is real or fake because I purchased this item and don’t know

Answer:

Double replacement

Explanation:

Answer:

581 Joules.

Explanation:

Using the formula;

Q = m × c × ∆T

Where;

Q = amount of heat absorbed (J)

m = mass of substance (g)

c = specific heat capacity (J/g°C)

∆T = change in temperature (°C)

According to the information provided in this question;

Q = ?

mass of ice = 15.9g

initial temperature = -4°C

final temperature = 14°C

Hence, ∆T = 14 - (-4) = 14 + 4 = 18°C

specific heat capacity (c) of ice in J/g°C = 2.03 J/g°C

Using Q = m × c × ∆T

Q = 15.9 × 2.03 × 18

Q = 32 × 18

Q = 581 Joules.

Answer:

Of course the answer is gold

Explanation:

Gold is used for making jewellery and not aluminium,iron or copper

Answer:

copper or gold.

Explanation:

Copper is also a good material for accessories. Even in the ancient times, those who can’t afford gold jewelry wear copper jewelry instead. It offers design flexibility too due to its high ductility.

Answer:

D

Explanation:

7 is neutral on a PH scale. Anything less is an acid and anything higher is a base. A Ph scale goes from 1-13. 8.4-7=1.4. This is a small change so it is considered a weak base. Can I get brainliest?

Answer:

D.A weak base

Explanation:

The pH of a weak base falls somewhere between 7 and 10. Like weak acids, weak bases do not undergo complete dissociation; instead, their ionization is a two-way reaction with a definite equilibrium point. While strong bases release hydroxide ions via dissociation, weak bases generate hydroxide ions by reacting with water. Ammonia (NH3) and methylamine (CH3NH2) are examples of weak bases.

There are two types of chemical compound one is covalent compound and other is ionic compound, covalent compound formed by sharing of electron and ionic compound formed by complete transfer of electron. Therefore, the correct option is option C.

Chemical Compound is a combination of molecule, Molecule forms by combination of element and element forms by combination of atoms in fixed proportion.

An ionic compound is a metal and nonmetal combined compound.  Ionic compound are very hard. They have high melting and boiling point because of strong ion bond.

Since phosphorus is a nonmetal, we need a metal. Out of given option the only element that is metal is Magnesium while others are non metal.

Therefore, the correct option is option C.

To learn more about chemical compound, here:

https://brainly.com/question/26487468

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Answer:

2NaOH + H₂SO₄ → Na₂SO₄ + 2H₂O

190.14 mL of the NaOH solution would be required.

Explanation:

The balanced reaction is:

Now we calculate how many H₂SO₄ moles are there in 25.00 mL of a 5.400 M solution, using the definition of molarity:

Now we convert H₂SO₄ moles into NaOH moles, using the stoichiometric coefficients of the balanced reaction:

Finally we calculate the volume of a 1.420 M solution that would contain 270 mmoles:

Answer:

Because of the electronegativity difference C-O (covalent) and Ca-O (ionic) bonds have.

Explanation:

Hello there!

In this case, in order to understand the polarity of this compound, calcium carbonate, it firstly necessary that it is comes from the definition of electronegativity, as a property defining the capacity to attract electrons from another atom; thus, since the electronegativities of calcium, carbon an oxygen are 1.0, 2.55 and 3.44, it is possible to realize this compound has O-Ca and O-C bonds according to its Lewis dot structure. In such a way, we calculate the difference electronegativity for these two bonds:

[tex]\Delta E_{O-Ca}=3.44-1.0 = 2.44\\\\\Delta E_{O-C}=3.44-2.55=0.89[/tex]

Thus, since 2.44 accounts for an ionic bond and 0.89 for a covalent one, we bear out the given statement in the question.

Answer:

22.98977 g/

Brainliest please

Answer:

molecular mass if Na  

2

​  

Co  

3

​  

=2×23×12+3×16

=46+12+48

=106

no.of mole =  

molecular wt.

Given wt.

​  

5=  

106

wt

wt=s30

​

Explanation:

Answer:

The answer is Y

Explanation:

:p

Answer:

nope its a myth don't worry :)

Answer:

Multicellular organisms thus have the competitive advantages of an increase in size without its limitations. They can have longer lifespans as they can continue living when individual cells die. Multicellularity also permits increasing complexity by allowing differentiation of cell types within one organism.

Answer:

sorry po

indi ko po maintindihan

Answer:

≅ 4.88 grams (3 sig. figs.)

Explanation:

to convert from ...

grams to moles => divide by formula wt.

moles to grams => multiply by formula wt.

this problem:

mass in grams = 488moles / 100.09g/mol = 4.875612 grams (calculator)

≅ 4.88 grams (3 sig. figs.)

Explanation:

[tex]pressure = 760mm \: of \: mercury \\ = 101325 \: pascals \\ from \: PV = nRT \\ 101325 \times 1 = n \times 8.314 \times 273 \\ n = 44.6 \: moles[/tex]

Answer:

740

Explanation:

The nitrogen is combined with it.

Answer:

D 8.8

Explanation:

To solve this question you must know that, using the kw equation:

Kw = 1x10⁻¹⁴ = [H⁺] [OH⁻]

-log 1x10⁻¹⁴ = -log ([H⁺] [OH⁻])

14= -log [H⁺] + -log [OH⁻]

As pH = -log[H⁺] and pOH = -log [OH⁻]

we can obtain the equation:

pH = 14 - pOH

As the pOH of the solution is 5.2:

pH = 14 - 5.2

pH = 8.8

Right option is:

The number of carbon atoms present in 1.25 mol of silver acetate is 1.875 × 10²³.

Avogadro's number is define as the number of atoms of any substance present in one mole of that substance, and it is equal to 6.022 × 10²³, i.e.
1 mole = 6.022 × 10²³ atoms/mol

Given moles of silver acetate = 1.25 moles

Number of atoms of silver acetate in 1.25 moles = 1.25 × 6.022 × 10²³ = 7.5×10²³

Molecular formula of silver acetate is CH₃CO₂Ag, means in this molecule total 8 atoms are present so number of carbon atom will be calculated as:

Carbon atoms = (2× 7.5 × 10²³) / 8 = 1.875 × 10²³ atoms [here we multiply by 2 because 2 atoms of carbon is present in olecule]

Hence required atoms of carbon is 1.875 × 10²³.

To know more about Avogadro's number, visit the below link:
https://brainly.com/question/1513182

hope it helps :-). good morning.

Answer:

3.6mol

Explanation:

The balanced chemical equation of this reaction is given as follows:

Ni + 2HF → NiF2 + H2

Based on the above equation, 2 moles of HF will react to produce 1 mole of NiF2.

According to this question, to make 174 grams of NiF2, we find the number of moles of HF required. However, we first convert the mass value of NiF2 to mole value using;

mole = mass/molar mass

Molar mass of NiF2 = 58.7 + 19(2)

= 58.7 + 38

= 96.7g/mol

mole = 174/96.7

mole = 1.799mol of NiF2

Hence, if 2 moles of HF will react to produce 1 mole of NiF2.

- 1.799mol of NiF2 will require (1.799 × 2) = 3.598

= 3.6mol of HF.

Answer:

sry i don't know that language

Answer: The value of acid ionization constant [tex]K_a[/tex] for acetic acid is [tex]1.87\times 10^{-5}[/tex]

Explanation:

[tex]CH_3COOH\rightarrow H^+CH_3COO^-[/tex]

 cM              0             0

[tex]c-c\alpha[/tex]        [tex]c\alpha[/tex]          [tex]c\alpha[/tex]  

So dissociation constant will be:

[tex]K_a=\frac{(c\alpha)^{2}}{c-c\alpha}[/tex]

Give c= 0.85 M and [tex]pH[/tex] = 2.4

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

[tex][H^=}=c\times \alpha=10^{-2.4}=3.98\times 10^{-3}[/tex]

[tex]K_a=?[/tex]

Putting in the values we get:

[tex]K_a=\frac{(3.98\times 10^{-3})^2}{(0.85-3.98\times 10^{-3})}=1.87\times 10^{-5}[/tex]

Thus the value of acid ionization constant [tex]K_a[/tex] for acetic acid is [tex]1.87\times 10^{-5}[/tex]

Answer:

1) it takes 13 second

2) 2100 miles

3) 40 miles / hours

4) 730 meters

Answer:

Done and done

Explanation:

Answer:

Hydroelectric pumped storage can be used to eliminate the conditional nature of wind and solar energy. At times of peak production of energy from either solar or wind (during summer and windy days), the excess electrical energy produced can be stored using hydroelectric pumped storage methods. When conditions no longer favour energy production from either wind or solar sources, these stored energy can then be regenerated for use.

Explanation:

Pumped-storage hydroelectricity is a type of hydroelectric energy storage used by electric power systems to store excess electrical power during periods of low demand for later release at periods when demand for energy rises again. It stores energy in the form of gravitational potential energy of water, pumped from a lower level reservoir to a higher level reservoir.

At times of low electrical demand, excess generated energy is used to pump water into the upper reservoir. When there is higher demand, water is released back into the lower reservoir through a turbine, generating electricity.

This form of energy storage is useful in circumventing the conditional nature of renewable energy sources such as wind and solar energy. At times of peak production of energy from either solar or wind (during summer and windy days), the excess electrical energy produced can be stored using hydroelectric pumped storage methods. When conditions no longer favour energy production from either wind or solar sources, these stored energy can then be regenerated for use.

Answer:

they help to calm the bees when the person keeping the bees inspects there hives.

Answer:

0.208333 M

Explanation:

M2=M1V1/V2=(0.25 M)(125mL)/(125mL+25 mL)= 0.208333 M

Answer:

Using dimensional analysis:

3.01x1022 molecules CO2 x 1 mol CO2/6.02x1023 molecules x 44. g CO2/mole = 2.20 g CO2

Explanation:

Answer:

A) chlorine

Explanation:

To solve this question we can use:

PV = nRT

In order to solve the moles of the gas. With the moles and the mass we can find the molar mass of the gas to have an idea of its identy:

PV = nRT

PV / RT = n

Where P is pressure: 603mmHg * (1atm / 760mmHg) = 0.7934atm

V = 100mL = 0.100L

R is gas constant = 0.082atmL/molK

T is absolute temperature = 14°C + 273.15 = 287.15K

0.7934atm*0.100L / 0.082atmL/molK*287.15K = n

3.37x10⁻³ moles of the gas

In 0.239g. The molar mass is:

0.239g / 3.37x10⁻³ moles = 70.9g/mol

The gas with this molar mass is Chlorine, Cl₂: