A physical property may be investigated by

The zinc within a copper-plated penny will dissolve in hydrochloric acid if the copper coating is filed down in several spots (s

Mrac [35]

Answer:

Mass of hydrogen gas evolved is 0.0749 grams.

Explanation:

Total pressure of the gases = p = 758 mmHg

Vapor pressure of water = 23.78 mmHg

Pressure of hydrogen gas ,P = p - 23.78 mmHg = 758 mmHg - 23.78 mmHg

P = 734.22 mmHg = $\frac{734.22}{760} atm=0.966 atm$

Temperature of of hydrogen gas ,T= 25°C =298.15 K

Volume of hydrogen gas = V = 0.949 L

Moles of hydrogen gas =n

PV = nRT (Ideal gas equation )

$n=\frac{PV}{RT}=\frac{0.966 atm\times 0.949 L}{0.0821 atm L/mol K\times 298.15 K}$

n = 0.03745 mol

Moles of hydrogen gas = 0.03745 mol

Mass of 0.03745 moles of hydrogen gas = 0.03745 mol × 2 g/mol = 0.0749 g

Mass of hydrogen gas evolved is 0.0749 grams.

3 0

3 years ago

Which of the following molecules are ionic?

kkurt [141]

1st one is E
2nd one is also E

6 0

2 years ago

Read 2 more answers

There are two binary compounds of mercury and oxygen. heating either of them results in the decomposition of the compound, with

grandymaker [24]

$\text{Hg} \text{O}$ and $\text{Hg}_{2} \text{O}$ .

Assuming complete decomposition of both samples,

$m(\text{Hg}) = m(\text{residure})$
$m(\text{O}) = m(\text{loss})$

First compound:

$m(\text{O}) = m(\text{loss}) = 0.6498 - 0.6018 = 0.048 \; g$
$m(\text{Hg}) = m(\text{residure}) = 0.6018 \; g$

$n = m/M$ ; $0.6498 \; g$ of the first compound would contain

$n(\text{O atoms}) = 0.048 \; g / 16 \; g \cdot mol^{-1}= 0.003 \; mol$
$n(\text{Hg atoms}) = 0.6018 \; g / 200.58 \; g \cdot mol^{-1}= 0.003 \; mol$

Oxygen and mercury atoms seemingly exist in the first compound at a $1:1$ ratio; thus the empirical formula for this compound would be $\text{Hg} \text{O}$ where the subscript "1" is omitted.

Similarly, for the second compound

$m(\text{O}) = m(\text{loss}) = 0.016 \; g$
$m(\text{Hg}) = m(\text{residure}) = 0.4172 - 0.016 = 0.4012 \; g$

$n = m/M$ ; $0.4172 \; g$ of the first compound would contain

$n(\text{O atoms}) = 0.016 \; g / 16 \; g \cdot mol^{-1}= 0.001 \; mol$
$n(\text{Hg atoms}) = 0.4012 \; g / 200.58 \; g \cdot mol^{-1}= 0.002 \; mol$

$n(\text{Hg}) : n(\text{O}) \approx 2:1$ and therefore the empirical formula

$\text{Hg}_{2} \text{O}$ .

8 0

3 years ago

Arun and Marcus are asked to compare the solubility of two salts in water at room temperature. The two salts are labelled X and

oksian1 [2.3K]

Answer:

1) Salts X and Y

2) The solubility of the salts

3) a) The solvent

b) The solvent temperature

Explanation:

1) The independent variable is the variable that is suspected to be the cause of the subject of the investigation

The given investigation is meant to investigate the solubility of different salts

Therefore, the solubility is expected to be dependent on the type of salt, and the independent variable is the type of salt, X or Y

2) The dependent variable is the effect meant to be observed in the investigation, which is the solubility of the salt in water at room temperature

3) The control variables are the variables which are held constant during the investigation, including;

a) The solvent used if the investigation; water

b) The temperature of the solvent; Room temperature

3 0

3 years ago

Consider the following reaction: 2CH3OH ---> 2CH4+O2 delta H= +252.8kJ. Calculate the amount of heat transferred when 22.0g o

nydimaria [60]

To calculate the amount of heat transferred when an amount of reactant is decomposed, we must look at the balanced reaction and its corresponding heat of reaction. In this case, we can see that 252.8 kJ of heat is transferred per 2 moles of CH3OH used. When 22 g of CH3OH is used, 86.9 kJ is absorbed.

4 0

2 years ago