Please help time is of the essence:

What is the density of a liquid if it has a mass of 12.9g ?

user100 [1]

Find it on google i’m pretty sure i saw it somewhere so sorry this doesn’t help

4 0

3 years ago

Which is generally stronger, intermolecular interactions or intramolecular interactions? Which is generally stronger, intermolec

Inessa [10]

Answer:

A. Intramolecular interactions are generally stronger.

B. a. Only intermolecular interactions are broken when a liquid is converted to a gas.

Explanation:

A. Which is generally stronger, intermolecular interactions or intramolecular interactions?

Intramolecular interactions, in which electrons are gained, lost or shared, constitute true bonds and are one or two orders of magnitude stronger than intermolecular interactions.

B. Which of these kinds of interactions are broken when a liquid is converted to a gas?

When a liquid vaporizes, the intermolecular attractions are broken, that is, molecules get more separated. However, true bonds are not broken which is why the molecules keep their chemical identity.

7 0

3 years ago

At which position is the northern hemisphere experiencing winter?

andrezito [222]

Answer:

Point A

Explanation:

The Northern Hemisphere is furthest away from the sun in position A. Therefore the sunlight takes longer to reach the Earth which results in the Northern Hemisphere experiencing winter.

7 0

2 years ago

7.00 of Compound x with molecular formula C3H4 are burned in a constant-pressure calorimeter containing 35.00kg of water at 25c.

beks73 [17]

Answer:

$\Delta H_{f,C_3H_4}=276.8kJ/mol$

Explanation:

Hello!

In this case, since the equation we use to model the heat exchange into the calorimeter and compute the heat of reaction is:

$\Delta H_{rxn} =- m_wC_w\Delta T$

We plug in the mass of water, temperature change and specific heat to obtain:

$\Delta H_{rxn} =- (35000g)(4.184\frac{J}{g\°C} )(2.316\°C)\\\\\Delta H_{rxn}=-339.16kJ$

Now, this enthalpy of reaction corresponds to the combustion of propyne:

$C_3H_4+4O_2\rightarrow 3CO_2+2H_2O$

Whose enthalpy change involves the enthalpies of formation of propyne, carbon dioxide and water, considering that of propyne is the target:

$\Delta H_{rxn}=3\Delta H_{f,CO_2}+2\Delta H_{f,H_2O}-\Delta H_{f,C_3H_4}$

However, the enthalpy of reaction should be expressed in kJ per moles of C3H4, so we divide by the appropriate moles in 7.00 g of this compound:

$\Delta H_{rxn} =-339.16kJ*\frac{1}{7.00g}*\frac{40.06g}{1mol}=-1940.9kJ/mol$

Now, we solve for the enthalpy of formation of C3H4 as shown below:

$\Delta H_{f,C_3H_4}=3\Delta H_{f,CO_2}+2\Delta H_{f,H_2O}-\Delta H_{rxn}$

So we plug in to obtain (enthalpies of formation of CO2 and H2O are found on NIST data base):

$\Delta H_{f,C_3H_4}=3(-393.5kJ/mol)+2(-241.8kJ/mol)-(-1940.9kJ/mol)\\\\\Delta H_{f,C_3H_4}=276.8kJ/mol$

Best regards!

7 0

2 years ago

A chemical reaction is occurring inside a beaker and the temperature of the beaker is monitored. What would the contents of the

Archy [21]

Answer:

The system is the Answer

Explanation:

System is the region which is taken into consideration.

While we perform a chemical reaction the system is the substance taken in the container.

So, A thermodynamic system is the amount of matter or the region in universe which is under the study.

The region outside the beaker are called as surroundings.

The beaker (the surface which separates the system from its surroundings) is said to be the boundary

System + surroundings = universe

3 0

2 years ago