All categories

4 years ago

Which of these statements best explains why chemistry is reliable?

Chemistry

1 answer:

Dominik [7]4 years ago

7 0

Answer:

It gives the same result when an experiment is repeated.

Explanation:

Below are the possible answers to the question:

It is biased.

It cannot be verified.

It cannot add new evidence to existing evidence.

It gives the same result when an experiment is repeated.

The correct answer would be that it gives the same result when an experiment is repeated.

If a reaction is conducted in chemistry and certain results are obtained, once a detailed procedure of the experiment is known along with all the chemicals involved, such reaction/experiment can be repeated anywhere in the world and the same result would be obtained.

The repeatability of experiments always makes the experiments to be reliable. Hence, chemistry is reliable because it gives the same result without any variation when experiments are repeated under similar conditions.

You might be interested in

6. What is the equilibrium constant for the following reaction? C+02 = CO2

Orlov [11]

<h3> $\tt Kc=\dfrac{[CO_2]}{[C][O_2]}$ </h3><h3>Further explanation</h3>

Given

Reaction

C+02 = CO2

Required

The equilibrium constant

Solution

The equilibrium constant is the ratio of concentration or pressure between the product and the reactant with each reaction coefficient raised

The equilibrium constant is based on the concentration (Kc) in a reaction

pA + qB -----> mC + nD

$\large {\boxed {\bold {Kc ~ = ~ \frac {[C] ^ m [D] ^ n} {[A] ^ p [B] ^ q}}}}$

So for the reaction :

C+O₂ ⇔ CO₂

$\tt Kc=\dfrac{[CO_2]}{[C][O_2]}$

8 0

3 years ago

onvert the value of Kc to a value of Kp for the following reaction: N2(g)+3H2(g)⇌2NH3(g) Kc = 0.50 at 400 °C.

ale4655 [162]

Answer:

$K_p= 0.00016$

Explanation:

The relation between Kp and Kc is given below:

$K_p= K_c\times (RT)^{\Delta n}$

Where,

Kp is the pressure equilibrium constant

Kc is the molar equilibrium constant

R is gas constant

T is the temperature in Kelvins

Δn = (No. of moles of gaseous products)-(No. of moles of gaseous reactants)

For the first equilibrium reaction:

$N_2_{(g)}+3H_2_{(g)}\rightleftharpoons2NH_3_{(g)}$

Given: Kc = 0.50

Temperature = $400^oC=[400+273]K=673K$

R = 0.082057 L atm.mol⁻¹K⁻¹

Δn = (2)-(3+1) = -2

Thus, Kp is:

$K_p= 0.50\times (0.082057\times 673)^{-2}$

$K_p= 0.00016$

6 0

3 years ago

A solid mixture consists of 47.6g of KNO3 (potassium nitrate) and 8.4g of K2SO4 (potassium sulfate). The mixture is added to 130

IgorLugansk [536]

Answer: No crystals of potassium sulfate will be seen at 0°C for the given amount.

Explanation:

We are given:

Mass of potassium nitrate = 47.6 g

Mass of potassium sulfate = 8.4 g

Mass of water = 130. g

Solubility of potassium sulfate in water at 0°C = 7.4 g/100 g

This means that 7.4 grams of potassium sulfate is soluble in 100 grams of water

Applying unitary method:

In 100 grams of water, the amount of potassium sulfate dissolved is 7.4 grams

So, in 130 grams of water, the amount of potassium sulfate dissolved will be $\frac{7.4}{100}\times 130=9.62g$

As, the soluble amount is greater than the given amount of potassium sulfate

This means that, all of potassium sulfate will be dissolved.

Hence, no crystals of potassium sulfate will be seen at 0°C for the given amount.

7 0

3 years ago

As a bond netween a hydrohen atom and sulfur atom is formed, electrons are

aleksley [76]

shared to form an ionic bond.

I hope this helps!

7 0

3 years ago

In a very violent reaction called a thermite reaction, aluminum metal reacts with iron (III) oxide to form iron metal and alumin

leva [86]

Here's the equation:
Fe2 O3 + 2Al → 2Fe + Al2 O3

Here's the question.
What mass of Al will react with 150g of Fe2 O3?

In every 2 moles Al you need 1 mole Fe2O3 

moles = mass / molar mass 
moles Fe2O3 = 150 g / 159.69 g/mol 
= 0.9393 moles 

moles Al needed = 2 x moles Fe2O3 
= 2 x 0.9393 mol 
= 1.879 moles Al needed 

mass = molar mass x moles 
mass Al = 26.98 g/mol x 1.879 mol 
= 50.69 g 
= 51 g (2 sig figs)

So the mass of Al that will react with 150g of Fe2 O3 is 51 grams.

3 0

4 years ago