Pls help really need it pls

Answer:

It can be expressed in several ways: molarity (moles of solute per liter of solution); mole fraction, the ratio of the number of moles of solute to the total number of moles of substances present; mass percentage, the ratio of the mass of the solute to the mass of the solution times 100; parts per thousand (ppt), grams ...

Explanation:

It can be expressed in several ways: molarity (moles of solute per liter of solution); mole fraction, the ratio of the number of moles of solute to the total number of moles of substances present; mass percentage, the ratio of the mass of the solute to the mass of the solution times 100; parts per thousand (ppt), grams ...

Answer:

An allotrope is one way that atoms can be arranged in a solid. An isotope is one way that protons and neutrons can form the same atomic element.

Answer:

Negative, because the potential energy of the reactants is higher than the potential energy of the products

Explanation:

Exothermic reaction is a reaction in which heat is released to surrounding. This is due to the fact that the heat content of the reactant is higher than the heat content of product thus producing a negative enthalpy change (ΔH) i.e

Enthalpy change = Heat of product – Heat of reactant

ΔH = Hp – Hr = negative

Considering the options given in the question above, the correct answer is:

Negative, because the potential energy of the reactants is higher than the potential energy of the products

Answer:

density= mass/volume

hence density of gold rock

= 386/20

=19.3 g/cc

Answer:

1. 10

Explanation

when litmus paper is blue that means the solution is basic and 10 on the pH scale is the most basic out of all your options

Answer:

The second division switches parts of matching chromatids to increase genetic variation.

Explanation:

Meiosis and fertilization create genetic variation by making new combinations of gene variants (alleles).

4) H+ions is your answer , good morning , have a great day ahead.

Answer:

energy

Explanation:

Answer:

Correct answer-C 5.3g

Explanation:

Molarity = no. of moles of solute/ volume of of solution in litre

olarity = no. of moles of solute/ volume of of solution in litreno of moles of solute = 0.125×0.25=0.03125

olarity = no. of moles of solute/ volume of of solution in litreno of moles of solute = 0.125×0.25=0.03125one mole AgNO3 weighs 169.87 gm,

olarity = no. of moles of solute/ volume of of solution in litreno of moles of solute = 0.125×0.25=0.03125one mole AgNO3 weighs 169.87 gm,so the mass of 0.03125 moles of AgNO3 = 0.03125×169.87= 5.3084g

The grams of AgNO₃ are needed to prepare 0.125 M solution in 250 mL of water is 5.3 grams.

Moles is a unit which is used to define any amount and it is calculated as:

n = W/M, where

W = required mass

M = molar mass

Given molarity of AgNO₃ = 0.125 M

Volume of water = 250mL = 0.25L

moles (n) from the molarity (M) will be calculated as:

n = M × V

n = (0.125)(0.25) = 0.0312 moles

Now we calculate the mass of AgNO₃ by using the above formula as:

W = (0.0312mol)(169.87g/mol)

W = 5.30 g

Hence option (c) is correct.

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Answer:

A. light energy is used in photosynthesis and created by respiration

Answer:

M = 12.0M

Explanation:

Hello there!

In this case, according to the given by-mass percent of HCl, which can be set up in terms of mass of HCl over mass of solution, we can calculate the molarity, by multiplying by the density to get the mL's of solution and further convert to liters. Moreover, the molar mass of HCl (36.46 g/mol) must be also used to calculate the moles, since molar units requires moles of solute and liters of solution as shown below:

[tex]M=\frac{37.0gHCl}{100g\ sln}*\frac{1.18g\ sln}{1mL\ sln}*\frac{1000mL\ sln}{1L \ sln}*\frac{1molHCl}{36.46gHCl}\\\\M= 12.0M[/tex]

Best regards!

Answer:

Temperature and precipitation

Explanation:

They determine how quickly weathering will be, and what kind of organic material may be available on the inside of the soils.

Temperature and precipitation is the major determining factor in soil formation. They define the type of organic material that can be present inside the soils as well as how rapidly weathering will occur.

The bioactive, porous media that has grown in the top layer of the Earth's crust is known as soil. Being a source of water as well as nutrients, a filter for harmful wastes, a site for their breakdown, and a participant inside the cycle of elements such as carbon through the planet's ecosystem, soil constitutes one of the main substrates of life on Earth.

It has changed as a result of weathering processes influenced by geographical, geologic, biological, and climatic factors. A practical understanding of soils including their management has also developed out of need since the development of agriculture with forestry in the eighth millennium BCE. Temperature and precipitation is the major determining factor in soil formation. They define the type of organic material that can be present inside the soils as well as how rapidly weathering will occur.

Therefore, temperature and precipitation is the major determining factor in soil formation.

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Answer:

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

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]

Most of the matter making up earth is composed of compounds. I think

Answer:

27J/Kmol

Explanation:

Heat = number of moles times the Moeller heat capacity chimes the change in temperature.

^ Q = nC△T

^ C = Q/ n△T = +53J / (1mol) (299.5K - 297.5K)

^ = 26.5 (rounded to 27)

Answer:

ye but sdfajkd tryng to play me

Explanation:

Answer:

Vapor is released out of the lemonade because when you place it in a hot it will increase.

Explanation:

Answer: ...

Explanation:

Sodium, chlorine

Answer:

2Na = 2 Sodium [has 2 atoms]

Cl2 = Dichlorine (Chlorine) [has 2 atoms]

Is this what you wanted?? I'm not entirely sure if this is the answer you were looking for.

Answer: The percent by mass concentration is 33.3 %

Explanation:

Mass percent is the ratio of mass of solute to the mass of solution in terms of percentage.

mass of solute = 50 g

mass of solution = [tex]{\text {density of solution}}\times {\text {volume of solution}}=1.5g/ml\times 1000ml=1500g[/tex]

Mass percentage = [tex]\frac{50g}{1500g}\times 100\%=33.3\%[/tex]

Thus percent by mass concentration of 1000 ml of a solution (d=1.5 g/ml) that contains 50 g of solute in it is 33.3 %

Answer:

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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:

i needed that lol

thank you

Explanation:

. Consider a sample of oxygen gas at 27° C with a volume of 9.55L at a pressure

Answer:620 k

Explanation:

Answer:

Here is every answer for analog and digital (in order)

Analog:

Digital (in order):

Explanation:

I did mine in bullet points, hopefully this helped!

Analog:

Signal Shape: Smooth and continuous

Numerical Values for Signal Estimations: Analog signals speak to one ceaseless variable as the result of another ceaseless time-based variable.

Amount of Information that can be transmitted: analog circuits can conduct as it were reasonably low-speed information communications.

Energy necessities: light, sound, temperature, position, and pressure Privacy and security : not encrypted

Clarity of Signal: clamor influences clarity and quality, commotion is amplified,

Digital:

Signal shape: stepping, square, and discrete

Numerical Values for Signal Measurements: digital communication methods transmit a complete measured value, in other words both a numeric value and a unit of measurement

Amount of data that can be transmitted: First of all, it is theoretically possible to transmit digital signals directly.

Energy requirements: voltage, accoustic pressure.

Privacy and security: encrypted

Clarity of signal: noise is lower in amplitude, electronics can ignore the noise, quality of signal is maintained, signal is high

Analog signal could be a continuous signal which speaks to physical estimations.

Digital signals are discrete time signals created by computerized balance.

Example :Human voice in discuss, analog electronic gadgets. Computers, CDs, DVDs, and other advanced electronic gadgets.

Answer:

Explanation:When silver Ag metal is added to copper sulphate CuSO4 solution, no reaction takes place as silver is less reactive than that of copper and cannot displace copper from its solution. Hence, when a piece of silver metal is added to copper sulphate solution there will be no reaction.

Answer:

There will be no reaction

Explanation:

Therefore, when silver Ag metal is added to copper sulphate CuSO4 solution, no reaction takes place as silver is less reactive than that of copper and cannot displace copper from its solution. Hence, when a piece of silver metal is added to copper sulphate solution there will be no reaction.

Answer:Matter is made up of only charged particles.

Explanation: Took the test

Answer:

0.208333 M

Explanation:

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

Answer:

Explanation:

Moles of Pb(NO3)2 =  mass/molecular mass

= 50.0 grams/(207.20*1 + 14.01*2 + 16*6)

= 50.0 grams/331.22

= 0.15 moles

Moles of NaI

= 30/(22.99+126.9)

= 30/149.89

= 0.2 Moles

A. NaI is less 2x Pb(NO3)2 so NaI is the limiting reagent.

B. The ratio is 1 to 2 so there is 0.15 - 0.2/2 = 0.05 mole

or 16.78 grams of Pb(NO3)2 left.

C. As NaI is limiting, only 0.2 Moles of NaNO3 is formed.

Mass =  Moles * Molecular Mass

Molecular Mass of NaNO3 can be calculated as:  

Na - 22.99

N - 14.01

O - 3(16) = 48

23+14+48 = 85gram / mole

Thus, Mass =  0.2*85  = 17 gram of NaNO3

Mass is conserved in a chemical reaction.

Mass of PbI2 can be calculated as:

50+30-16.78-17

= 46.3 gram of PbI2

Mass =  

12.75

Thus, 12.75g of Sodium Nitrate can be formed

Answer:

Explanation:

Pb(NO3)2 (aq) + 2 NaI (aq) --> PbI2 (s) + 2 NaNO3 (aq)

MM for each compound -

Pb(NO3): 207 + 14x2 + 16x3x2 = 331

PI2: 207 + 127x2 = 461

NaI: 23 + 127 = 150

NaNO3: 23 + 14 + 16x3 = 85

Moles of Pb(NO3)2 = 50/331 = 0.15

Moles of NaI = 30/150 = 0.2

Ratio of moles is 1:2

So NaI is limiting

Limited to 0.2/2 = 0.1 mole of Pb(NO3)2

Excess = 0.15 - 0.1 = 0.05 mole

Mass remains = 0.05x331 = 16.55 grams

Moles of NaNO3 formed = Moles of NaI reacted = 0.2

Mass = 0.2x85 = 17 grams

Moles of PbI2 formed = Moles of Pb(NO3)2 reacted = 0.1

Mass = 0.1x461 = 46.1 grams

If 12 grams of NaNO3 actually formed in the reaction,

percent yield = 12/17x100% = 70.6%