Two pieces of iron with the different masses - 500 g and 1000 g - both have 4.5 kJ of energy added to them.

A student conducts an experiment by placing a wooden stick in a cup of sugar solution. Over the next few weeks, sugar crystals f

Ipatiy [6.2K]

Answer: In order to be alive there must be cells present and since sugar does not contain cells it is not alive.

Explanation:

8 0

2 years ago

A gaseous mixture composed of 20% CH4, 30% C2H4, 35% C2H2, and 15% C2H20. What is the average molecular weight of the mixture? a

Semenov [28]

Answer: The correct answer is Option d.

Explanation:

We are given:

Mass percentage of $CH_4$ = 20 %

So, mole fraction of $CH_4$ = 0.2

Mass percentage of $C_2H_4$ = 30 %

So, mole fraction of $C_2H_4$ = 0.3

Mass percentage of $C_2H_2$ = 35 %

So, mole fraction of $C_2H_2$ = 0.35

Mass percentage of $C_2H_2O$ = 15 %

So, mole fraction of $C_2H_2O$ = 0.15

We know that:

Molar mass of $CH_4$ = 16 g/mol

Molar mass of $C_2H_4$ = 28 g/mol

Molar mass of $C_2H_2$ = 26 g/mol

Molar mass of $C_2H_2O$ = 48 g/mol

To calculate the average molecular mass of the mixture, we use the equation:

$\text{Average molecular weight of mixture}=\frac{_{i=1}^n\sum{\chi_im_i}}{n_i}$

where,

$\chi_i$ = mole fractions of i-th species

$m_i$ = molar masses of i-th species

$n_i$ = number of observations

Putting values in above equation:

$\text{Average molecular weight}=\frac{(\chi_{CH_4}\times M_{CH_4})+(\chi_{C_2H_4}\times M_{C_2H_4})+(\chi_{C_2H_2}\times M_{C_2H_2})+(\chi_{C_2H_2O}\times M_{C_2H_2O})}{4}$

$\text{Average molecular weight of mixture}=\frac{(0.20\times 16)+(0.30\times 28)+(0.35\times 26)+(0.15\times 42)}{4}\\\\\text{Average molecular weight of mixture}=6.75$

Hence, the correct answer is Option d.

3 0

3 years ago

Why do the pH scale generally range from 0 to 14 in aqueous solution?

zalisa [80]

Answer:

In aqueous solution the pH scale varies from 0 to 14, which indicates this concentration of hydrogen. Solutions with pH less than 7 are acidic (the value of the exponent of the concentration is higher, because there are more ions in the solution) and alkaline (basic) those with a pH higher than 7. If the solvent is pure water, the pH = 7 indicates neutrality of the solution

Explanation:

PH is a measure of how acidic or basic a liquid is. Specifically, from a dissolution. The acidity of a solution is essentially due to the concentration of hydrogen ions dissolved in it. In reality, the ions are not found alone, but are in the form of hydronium ions consisting of one oxygen molecule and three positively charged hydrogen. PH precisely measures this concentration. And to do it, we can use simple and very visual methods.

5 0

3 years ago

B) How many kilograms of carbon dioxide are formed when 24.42 g of iron is produced?

charle [14.2K]

Answer:

0.0289 kg of CO2 will be formed

Explanation:

Step 1: Data given

Mass of iron produced = 24.42 grams

Atomic mass iron = 55.845 g/mol

Molar mass CO2 = 44.01 g/mol

Step 2: The balanced equation

Fe2O3 + 3CO → 2Fe + 3CO2

Step 3: Calculate moles iron

Moles iron = mass iron / molar mass iron

Moles iron = 24.42 grams / 55.845 g/mol

Moles iron = 0.437 moles

Step 4: Calculate moles CO2

For 1 mol Fe2O3 we need 3 moles CO to produce 2 moles Fe and 3 moles CO2

For 0.437 moles Fe we'll have 3/2 * 0.437 = 0.6555 moles CO2

Step 5: Calculate mass CO2

Mass CO2 = moles CO2 * molar mass CO2

Mass CO2 = 0.6555 moles * 44.01 g/mol

Mass CO2 = 28.85 grams = 0.0289 kg

0.0289 kg of CO2 will be formed

5 0

3 years ago

HELP PLEASE THE OTHER 'ANSWER' ISNT EVEN AN ANSWER!

hodyreva [135]

Answer:

most likely that (2) the replicated experiment was performed incorrectly.

Why, u ask? u dare question me:

1- The initial experiment invalidness cannot be proven.

2- the second answer is correct

3- Different labaratories does not effect the outcome, as long as the parameter and environment of the replicated experiment is the same as when the initial experiment was conducted.

4- Already knowing the data and errors would increase the precision of the replicated experiment.

5- Change in variables should still be in the objective (or purpose) of the experiment, thus, major difference in the outcome should not happen.

happy learning!

4 0

3 years ago