Which among the following mixtures will show tyndal effect?
i) copper sulphate solution
ii) sand in water.
iii) milk.
iv) starch solution ​

Explanation:in testing for oxygen a glowing splint is used.

the glowing splint is brought in the presence of the test tube containing the gas

the glowing splint rekindles or lights up showing that oxygen is present.

this is a positive test because oxygen supports burning or combustion

Answer:

0.289J of heat are added

Explanation:

We can relate the change in heat of a substance with its increasing in temperature using the equation:

q = m*ΔT*S

Where Q is change in heat

m is mass of substance (In this case, 0.0948g of water)

ΔT = 0.728°C

S is specific heat (For water, 4.184J/g°C)

Replacing:

q = 0.0948g*0.728°C*4.184J/g°C

q = 0.289J of heat are added

Water is the solvent in the saline solution. Hence, option D is correct.

A solute is something being dissolved, a solvent is a thing dissolving the item, and the solution is the mixture of the two items.

In a hospital, bags of saline solution are used to rehydrate patients. They are made by dissolving a specific amount of salt in water. Water is the solvent in the saline solution.

Hence, option D is correct.

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Explanation:

HI friends good morning

Answer:

62.5 moles of O₂.

Explanation:

We'll begin by writing the balanced equation for the reaction. This is illustrated below:

2C₈H₁₈ + 25O₂ —> 16CO₂ + 18H₂O

From the balanced equation above,

2 moles of C₈H₁₈ reacted with 25 moles of O₂.

Finally, we shall determine the number of mole of O₂ needed to react with 5 moles of C₈H₁₈. This can be obtained as shown below:

From the balanced equation above,

2 moles of C₈H₁₈ reacted with 25 moles of O₂.

Therefore, 5 moles of C₈H₁₈ will react with = (5 × 25) / 2 = 62.5 moles of O₂.

Thus, 62.5 moles of O₂ is needed for the reaction.

Answer:

e.

6.7

hope it help

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.

.

.

.

.

Answer:

C.

Explanation:

Answer A is incorrect because a compound doesn't have to be made with only metals.

Answer B is incorrect because that is actually the definition of a pure element.

Answer C is correct because to make a compound, there has to be a chemical reaction where bonds are formed and an entirely new substance is created.

Answer D is incorrect because compounds cannot be separated by physical means.

Hope this helps :D

Answer:

1;1, 2;1, 3;1, 1;2, 1;1, 3;2, 1;3, 2;3, 1;1.

I hope this will help.

Answer:

This is what the answer looks like

Explanation:

Answer:

C 760 mm of hg

because this is the atmospheric pressure at sea level

Explanation:

a) m (metre)

b) mm (millimeter)

Answer:

a

Explanation:

Answer:

For example, the bond between the sodium and chlorine atoms in sodium chloride (NaCl) is formed by the transfer of an electron from sodium to chlorine, creating Na + and Cl – ions. ... The electrostatic attraction between these ions provides the bonding in NaCl.

Answer:  1)  temperature, 2) add a catalyst, and 3) concentrations

Explanation:  A rise in temperature adds kinetic energy to the reactants, leading to more frequent, and energetic collisions, which will often accelerate the reaqction.  A catalyst is an agent that helps the reaction move forward more quickly by offering a substrate that aids in orienting the reactants for more efficient reaction.  A higher concentration increases the chances of collisons that result in products.

You're going to first balance the chemical equation.

After that, convert the grams of Na into moles of Na, and then multiply that with the ratio of moles of NaCl to Na, and then convert the mol of NaCl into grams in order to obtain the theoretical yield, since we are given that Na is the limiting reactant.

After that, plug the values into the yield formula, doing some basic algebra, and you should get your result.

You're going to first balance the chemical equation.

After that, convert the grams of Na into moles of Na, and then multiply that with the ratio of moles of NaCl to Na, and then convert the mol of NaCl into grams in order to obtain the theoretical yield, since we are given that Na is the limiting reactant.

After that, plug the values into the yield formula, doing some basic algebra, and you should get your result.

Answer:

A. 36 percent recieved Bs

B. 40 percent of students received Cs

Explanation:

Amount of students: 12+18+20=50

Students with Bs: (18÷50) x 100 = 36%

Students with C's: (20÷50) x100 = 40%

On the first chemistry test 12 students got A, 18 students got B, and 20 student got C. Thus the percentage of students received B is 0.36 and percentage of students received c is 0.40

In mathematics, a number or ratio expressed as a fraction of 100. It is often denoted using the percent sign %. A percentage is a dimension less unit and it has no unit.

In above question 12 student got A, 18 student got B, and 20 student got C.

So total number of student = 12 + 18 + 20 = 50.

Then the percentage of students received B is as follows:-

Percentage of students who got B = (student who got B/Total number of student) X 100.

=(18/50) X 100

= 36%

Now percentage of students who got C = (No of students who got C/Total students)X100

=(20/50) X 100

=40%.

Therefore,On the first chemistry test 12 students got A, 18 students got B, and 20 student got C. Thus the percentage of students received B is 0.36 and percentage of students received c is 0.40 percentage of students who got B is 36% and percentage of students who got C is 40%

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Answer:

if wrong sorry ok????

Answer:

7.2

Explanation:

you first have to find the number of moles of nitrogen dioxide by using the number of moles for calcium nitrate and the mole to mole ratios

number of moles of calcium nitrate=mass/mm

=16.4/102

=0.16g/mol

then you use the mole to mole ratios

2 : 4

0.16: x

2x/2=0.64/2

x=0.32g/moles of nitrogen dioxide

then you use the formula for the volume

v=22.4n

=22.4×0.32

=7.2

I hope this helps

Answer:

c2h4 (etthane........

bexcuse it has 6 bond of hydrogen

C₂H₄ molecules contains six bonding electrons. Therefore, option A is correct.

Chemical bonding is the process through which two or more atoms, molecules, or ions establish a chemical link to create a chemical compound. The atoms in the resultant molecule are held together by these chemical bonds.

Chemical bonds have three basic characteristics that must be taken into account: their strength, length, and polarity. The distribution of electrical charge among the atoms connected by a bond determines its polarity.

C₂H₄ molecules has six bonding electrons. This molecule is called as Ethylene. When bonding is done between two atoms, each atom shares a pair of electrons with each other.

Hence, for every one bond, two electrons are shared between two atoms

Thus, option A is correct.

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The scientific question related to the game of basketball is option D: "Do teams that practice more win more games?"

This question is scientific because it explores a cause-and-effect relationship between practice and game outcomes. It can be investigated through empirical observation and data analysis.

To answer this question, researchers could collect data on the practice hours of different basketball teams and compare them to their corresponding game performance. Statistical analysis could be used to determine if there is a correlation between practice time and winning percentage or other performance metrics.

By examining a large sample of teams over an extended period, researchers could draw conclusions about the impact of practice on game outcomes. This scientific inquiry would contribute to the understanding of the factors that influence team success in basketball and could potentially inform training strategies and coaching techniques.

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Answer:

sodium chloride

hope that helped :)

Answer:

Chlorine is a greenish yellow gas at room temperature and atmospheric pressure. ... yielding chlorine water, and from this solution a solid hydrate of ideal ...

Answer:

337.5kPa ~ 338kPa

Explanation:

Using the ideal gas law PV=nRT we have the following definitions from the problem:

V(initial) = 20cm³

P(initial) = ?kPa

V(final) = 75cm³

P(final) = 90kPa

Since we know that the number of moles of the sample did not change, nor did the temperature, nor does the ideal gas constant (R) we can rewrite this equation to state:

P(initial)V(initial) = nRT =P(final)V(final) ~  P(initial)V(initial) = P(final)V(final)

Rearranging this equation as we are solving for the initial pressure we find that:

P(initial) = (P(final)V(final))/V(initial)

P(initial) = ((90kPa)(75cm³))/20cm³

P(initial) = 337.5kPa ~ 338kPA

Answer:

See explanation

Explanation:

Tyndall effect refers to the scattering of light in a solution. Tyndall effect occurs when the size of particles in the solution exceeds 1 nm in diameter. Such solutions are actually called false solutions.

In tincture of iodine, the size of particles in solution is less than 1 nm in diameter hence the solution does not exhibit Tyndall effect. Hence, tincture of iodine is a true solution.

Therefore, if the size of particles in solution exceeded 1nm in diameter, Tyndall effect is observed.

Answer:

1. 2.63x10^6

2. 39.2

Both answers have been rounded

Answer:

C2H4 Ethylene

Explanation:

Hope it helps! :)

Answer:

Explanation:

Lithium Sulphate

Answer:

Lithium sulfate is a white inorganic salt with the formula Li2SO4. It is the lithium salt of sulfuric acid.

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The pressure in atm exerted by 1.8 g of H₂ gas exert in a 4.3 L balloon at 27ºC is 5.12 atm

The ideal gas law (PV = nRT) relates the macroscopic properties of ideal gases. An ideal gas is a gas in which the particles (a) do not attract or repel one another and (b) take up no space (have no volume).

Let's convert grams to moles (via molar mass).

Molar Mass (H₂) :  2 (1.008 g/mol)

Molar Mass (H₂) :  2.016 g/mol

1.8 grams H₂               1 mole

----------------------  x  ----------------------  =  0.893 moles H₂

                                2.016 grams

The Ideal Gas Law equation looks like this:

PV = nRT

In this equation,

After converting Celsius to Kelvin, you can put the given values into the equation and simplify to find the pressure.

P = ? atm                                R = 0.0821 L*atm/mol*K

V = 4.3 L                               T = 27 °C + 273.15 = 300.15 K

n = 0.893 moles

PV = nRT

P (4.3 L) = (0.893 moles) (0.0821 L*atm/mol*K)( 300.15 K)

P (4.3 L) =  22.0021

P = 5.12 atm

Therefore, The pressure in atm exerted by 1.8 g of H₂ gas exert in a 4.3 L balloon at 27ºC is 5.12 atm

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