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3 years ago

Complete the following paragraph.

Chemistry

1 answer:

gladu [14]3 years ago

3 0

Explanation:

the stationary phase in TLC is a silica gel coated metal plate or paper.

The individual component of the mixure will travel a greater distance up the plate, resulting in a Rf value for the component.

the p-Xylene spot will travel a greater distance as it is the lighter component

Bromobenzene will travel least as it is the heavier component.

thin layer chromatography (TLC) is a type of chromatographic seperation technique that is based on the molecular size of components. the Rf value is the distance covered by the component relative to that travelled by the solvent which is the mobile phase

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Whch is more acidic, a solution with a pH of 2 or 5

Molodets [167]

Answer:

A solution with a pH of 2

Explanation:

The lower a pH is in a liquid, the more acidic it is. 7 is the neutral pH for a liquid. We usually drink around that pH for water. A pH higher than 7 expresses that the liquid is a base.

3 0

3 years ago

Read 2 more answers

Calculate the energy, in joules, to heat two cubes (silver and copper), each with a volume of 10.0cm, from 15 C to 25 C

Julli [10]

Answer:

For Silver , The heat absorbed = 246.75 J

For Copper , The heat is = 343.42 J

Explanation:

The change in temperature is calculated by:

$\Delta T=T_{2}-T_{1}$

T2 = 25 C

T1 = 15 C

$\Delta T=25-15$

$\Delta T=10^{0}C$

The energy in Joules can be calculated using :

$q=mc\Delta T$

here , m = mass of the substance

c = the heat capacity

q = heat absorbed / released

We need to calculate the mass , In order to determine the value of "q".

Calculation for Silver :

The mass is calculated from the density of the element.

density of Silver = 10.5 g/ml (look at the table of density)

Volume of Cube = 10 cm^3 (given)

1 cm^3 = 1 mL

10 cm^3 = 10 mL

The mass can be calculated using the formula:

$mass = density\times Volume$

$mass = 10.5\times 10$

$mass = 105grams$

Insert the value of m , c, T in the equation.

for Silver the value of "c"= 0.235 J/gC (Look at the table)

$q=mc\Delta T$

$q=105\times 0.235\times 10$

$q=246.75J$

Calculation for Copper:

Again first calculate the mass of Copper.

Density of Copper = 8.92 g/ml

Volume = 10 mL

$mass = density\times Volume$

$mass = 8.92\times 10$

$mass = 89.2grams$

Insert the value of m , c, T in the equation.

for Silver the value of "c"= 0.385 J/gC (Look at the table)

$q=mc\Delta T$

$q=89.2\times 0.385\times 10$

$q=343.42J$

8 0

3 years ago

Veronica is taking an average of 16 height measurements in a brand-new experiment. Which term is this the best example of?

Varvara68 [4.7K]

Answer:

Repetition

Explanation:

The best term to describe this example is repetition and not replication.

Most times, to obtain an accurate and precise reading which is reliable, scientist makes several repeated measurements. The average gives the most reliable representation of the phenomenon being tested.

This process is called repetition.

On the other hand, duplicating an experiment is replication. Experiments are replicated to proof their validity.

Since this is a brand new experiment where 16 height measurements are reported, we are dealing with a repetition situation.

4 0

3 years ago

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How many grams S03 are needed to make 400g H₂So4 in 49%

NemiM [27]

160 g of SO3 are needed to make 400 g of 49% H2SO4.

<h3>How many grams of SO3 are required to prepare 400 g of 49% H2SO4?</h3>

The equation of the reaction for the formation of H2SO4 from SO3 is given below as follows:

$SO_{3} + H_{2}O \rightarrow H_{2}SO_{4}$

1 mole of SO3 produces 1 mole of H2SO4

Molar mass of SO3 = 80 g/mol

Molar mass of H2SO4 = 98 g/mol

80 g of SO3 are required to produce 98 og 100%H2SO4

mass of SO3 required to produce 400 g of 100 %H2SO4 = 80/98 × 400 = 326.5 g of SO3

Mass of SO3 required to produce 49% of 400 g H2SO4 = 326.5 × 49% = 160 g

Therefore, 160 g of SO3 are needed to make 400 g of 49% H2SO4.

Learn more about mass and moles at: brainly.com/question/15374113

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7 0

2 years ago

Nuclear decay is more likely to occur when?

Maru [420]

Answer:

Radioactive decay occurs in unstable atomic nuclei – that is, ones that don't have enough binding energy to hold the nucleus together due to an excess of either protons or neutrons.

Hope this helps!

6 0

4 years ago

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