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A chemical reaction takes place inside a flask submerged in a water bath. The water bath contains 8.10kg of water at 33.9 degree

lions [1.4K]

Answer:

The new temperature of the water bath 32.0°C.

Explanation:

Mass of water in water bath ,m= 8.10 kg = 8100 g ( 1kg = 1000g)

Initial temperature of the water = $T_1=33.9^oC=33.9+273K=306.9 K$

Final temperature of the water = $T_2$

Specific heat capacity of water under these conditions = c = 4.18 J/gK

Amount of energy lost by water = -Q = -69.0 kJ = -69.0 × 1000 J

( 1kJ=1000 J)

$Q=m\times c\times \Delta T=m\times c\times (T_2-T_1)$

$-69.0\times 1000 J=8100 g\times 4.18 J/g K\times (T_2-306.9 K)$

$-69,000.0 J=8100 g\times 4.18 J/g K\times (T_2-306.9 K)$

$T_2=304.86 K=304.86 -273^oC=31.86^oC\approx 32.0^oC$

The new temperature of the water bath 32.0°C.

5 0

4 years ago

The decomposition of methanol, ch3oh(g), to form ch4(g) and o2(g) absorbs 252.8 kj of heat per mole of oxygen formed. write a ba

Svetllana [295]

The thermochemical equation is the chemical equation including the net change of enthalpy (heat).

The chemical equation for the decomposition of methanol to form methane and oxygen is:

2CH3OH --> 2CH4 + O2

The thermochemical equation is:

2CH3OH ---> 2CH4 + O2 - 252.8 kJ

Note that the heat is placed as negative at the right side because it is absorbed during the decomposition, so the environment will have 252.8 kJ less per each mole of O2 produced.

You can equivalently write:

2CH3OH + 252.8 kJ --> 2CH4 + O2

4 0

4 years ago

In which of the following compounds does the carbonyl stretch in the IR spectrum occur at the lowest wavenumber?

klio [65]

Answer:

a. Cyclohexanone

Explanation:

The principle of IR technique is based on the vibration of the bonds by using the energy that is in this region of the electromagnetic spectrum. For each bond, there is a specific energy that generates a specific vibration. In this case, you want to study the vibration that is given in the carbonyl group C=O. Which is located around 1700 cm-1.

Now, we must remember that the lower the wavenumber we will have less energy. So, what we should look for in these molecules, is a carbonyl group in which less energy is needed to vibrate since we look for the molecule with a smaller wavenumber.

If we look at the structure of all the molecules we will find that in the last three we have heteroatoms (atoms different to carbon I hydrogen) on the right side of the carbonyl group. These atoms allow the production of resonance structures which makes the molecule more stable. If the molecule is more stable we will need more energy to make it vibrate and therefore greater wavenumbers.

The molecule that fulfills this condition is the cyclohexanone.

See figure 1

I hope it helps!

4 0

4 years ago

ENTER THE COEFFICIENTS DIRECTLY FROM THE BALANCED CHEMICAL EQUATION. do not reduce to lowest terms. for example: if 3 moles H2 r

dlinn [17]

Answer:

The coefficients are 2 for H₂O and 1 for Ca(OH)₂.

Explanation:

Let's consider the following reaction.

Ca(OH)₂(aq) + 2 HCl(aq) → CaCl₂(aq) + 2 H₂O(l)

According to the balanced equation, the molar ratio of H₂O to Ca(OH)₂ is 2:1. Using this conversion factor, we have the following proportion:

moles Ca(OH)₂. (2 mol H₂O ÷ 1 mol Ca(OH)₂) = moles H₂O

4 0

3 years ago

Ocean tides on earth MOST influenced by gravity from the __

Ivahew [28]

Answer:

moon

Explanation:

the moon's gravitational pull generates tidal force which affects earth's tides

8 0

3 years ago