What is the suitable way of investigating the different food colourings in some drinks ?

Todd drives west to work;54km on way in 1.5hours and then drives home in 2hrs. What is his velocity on the way to work? What is

Nataly [62]

Answer:

Explanation:

Velocity is a physical quantity that expresses the relationship between the space traveled by an object, the time taken for it and its direction. In other words, velocity is associated with the change of position of a body over time.

Its unit in the International System of Units is the meter per second ( $\frac{m}{s}$ ), but it can also be expressed in $\frac{km}{hr}$

So, in this case, the speed on the way to work will be:

$velocity=\frac{54 km}{1.5 hours}$

velocity= 36 $\frac{km}{hr}$

The velocity on the way back home will be:

$velocity=\frac{54 km}{2 hours}$

velocity= 27 $\frac{km}{hr}$

7 0

3 years ago

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Which of the following is NOT how compounds are formed?

cricket20 [7]

Compounds are not formed by accepting electrons. Number 1 and 3 are correct.

5 0

3 years ago

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rate of a certain reaction is given by the following rate law: rate Use this information to answer the questions below. What is

Sunny_sXe [5.5K]

Complete Question

The rate of a certain reaction is given by the following rate law:

$rate = k [H_2][I_2]$

rate Use this information to answer the questions below.

What is the reaction order in $H_2$ ?

What is the reaction order in $I_2$ ?

What is overall reaction order?

At a certain concentration of H2 and I2, the initial rate of reaction is 2.0 x 104 M / s. What would the initial rate of the reaction be if the concentration of H2 were doubled? Round your answer to significant digits. The rate of the reaction is measured to be 52.0 M / s when [H2] = 1.8 M and [I2] = 0.82 M. Calculate the value of the rate constant. Round your answer to significant digits.

Answer:

The reaction order in $H_2$ is n = 1

The reaction order in $I_2$ is m = 1

The overall reaction order z = 2

When the hydrogen is double the the initial rate is $rate_n = 4.0*10^{-4} M/s$

The rate constant is $k = 35.23 \ M^{-1} s^{-1}$

Explanation:

From the question we are told that

The rate law is $rate = k [H_2][I_2]$

The rate of reaction is $rate = 2.0 *10^{4} M /s$

Let the reaction order for $H_2$ be n and for $I_2$ be m

From the given rate law the concentration of $H_2$ is raised to the power of 1 and this is same with $I_2$ so their reaction order is n=m=1

The overall reaction order is

$z = n +m$

$z =1 +1$

$z =2$

At $rate = 2.0 *10^{4} M /s$

$2.0*10^{4} = k [H_2] [I_2] ---(1)$

= > $k = \frac{2.0*10^{4}}{[H_2] [I_2] }$

given that the concentration of hydrogen is doubled we have that

$rate = k [2H_2] [I_2] ----(2)$

=> $k = \frac{rate_n }{ [2H_2] [I_2]}$

So equating the two k

$\frac{2.0*10^{4}}{[H_2] [I_2] } = \frac{rate_n }{ [2H_2] [I_2]}$

=> $rate_n = 4.0*10^{-4} M/s$

So when

$rate_x = 52.0 M/s$

$[H_2] = 1.8 M$

$[I_2] = 0.82 \ M$

We have

$52 .0 = k(1.8)* (0.82)$

$k = \frac{52 .0}{(1.8)* (0.82)}$

$k = 35.23 M^{-2} s^{-1}$

3 0

3 years ago

Describe the crystallization process as applied in salt preparation

shtirl [24]

Explanation:

The principle used in the preparation of these salts is to dissolve

the cystine in an alcoholic alkali solution to which just sufficient

water to effect solution has been added, and, after filtering from

excess cystine, to precipitate the salt by addition of a suitable

indifferent solvent. While various solvents, such as acetone,

ether, or large amounts of alcohol caused precipitations, these were

either oily or amorphous. Only acetonitrile was found to possess

the power of initiating regular crystallization in the salt solutions.

While the solutions of the different salts require different amounts

of the solvent for complete precipitation, a partial substitution of

absolute ether for acetonitrile was found expedient in the case

of the most soluble of the salts, the K salt.

6 0

3 years ago

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If the mole fraction of sulfuric acid H2SO4 is 0.432 what is the percent by mass of H2SO4.

Sever21 [200]

Answer:

19.47%

Explanation:

The percentage by mass of $H_2SO_4$ would be 19.47%.

The percentage by mass of a substance in solution is calculated as:

$\frac{mass of substance}{mass of substance + water} * 100%$

Given that the mole fraction of $H_2SO_4$ = 0.432

The total number of mole fraction of a solution = 1

Hence, mole fraction of water = 1 - 0.432 = 0.568

Mass of water = molar mass x mole

= 98.079 x 0.432 = 42.37 g

Mass of $H_2SO_4$ = molar mass x mole

= 18.02 x 0.568 = 10.24 g

Hence,

%mass of $H_2SO_4$ = $\frac{10.24}{10.24 + 42.37} * 100$

= 19.47%

4 0

3 years ago