How many moles of pb(so4) can be made from the reaction of 330.g Li2SO4

The eastern coast of South America and the western coast of Africa are separated by the Atlantic Ocean. If scientists find the s

sergey [27]

Answer:

At one time the two continents were one landmass

Explanation:

If scientists find the same types of plant fossils on the eastern coast of South America and the western coast of Africa, this suggests that at one time, the two continents were one landmass. When the continents separated, the communities of plants were split, resulting in identical fossils on each coast millions of years later.

7 0

3 years ago

What type of chemical reaction is the reaction below?Fe2O3 + 3 Mg --> 2 Fe + 3 MgO

gogolik [260]

Answer:

Replacement reaction or Single displacement reaction

Explanation:

Here, we want to know the kind of chemical reaction shown

As we can see here, the magnesium atom displaced the iron atom from its oxide

This is due to the fact that magnesium has a higher position in the elctrochemical series

This kind of reaction is called a replacement reaction or a single displacement reaction

5 0

1 year ago

How long is radioactive waste from nuclear plants radioactive?

Anettt [7]

Answer:about 10,000 years b maybe

Explanation:Strontium-90 and cesium-137 have half-lives of about 30 years (half the radioactivity will decay in 30 years). Plutonium-239 has a half-life of 24,000 years. High-level wastes are hazardous because they produce fatal radiation doses during short periods of direct exposure.

8 0

3 years ago

Read 2 more answers

For a particular reaction, Δ H = 120.5 kJ / mol and Δ S = 758.2 J / ( mol⋅K). Calculate Δ G for this reaction at 298 K. Δ G = kJ

lilavasa [31]

Answer:

ΔG = -105.4 kJ/mol

The system is spontaneous as written.

Explanation:

Step 1: Determine Gibbs free energy of reaction (ΔG)

We use the following expression.

ΔG = ΔH - T × ΔS

where,

ΔH: enthalpy of reaction

T: absolute temperature

ΔS: entropy of reaction

ΔG = ΔH - T × ΔS

ΔG = 120.5 kJ/mol - 298 K × 0.7582 kJ/mol.K

ΔG = -105.4 kJ/mol

Step 2: Determine the spontaneity of the system.

Since ΔG < 0, the system is spontaneous as written.

6 0

3 years ago

The heat of combustion of wood is approximately 16 kJ/g. What is the final temperature that 500.0 mL of water, initially at 25.0

marissa [1.9K]

Answer:

The final temperature is 34,2 ºC when 1,20 g of wood is burned inside the calorimeter.

Explanation:

The heat of combustion of wood which is approximately 16 kJ/g means that 1 g requires 16 kJ of heat so let's calculate about 1,20 g which is the value of wood you have.

1 g ________ 16 kJ

1,20 g ______ 1,20 g x 16 kJ = 19,2 kJ = 19200 J

Now let's apply the calorimetry formula

Q = m . C . ΔT

19200 J = 500 g . 4,186 J/ gºC ( Tfinal - 25ºC)

<em>Look that we don't have the mass of water, instead we have the volume so as you know water density is 1 g/ml, we conclude that in 500 ml, we have 500 g.</em>

On the other hand we convert the 19.2 kJ into J (* 1000) by the units in the value of the specific heat of the water, it is in Joule

19200 J = 500 g . 4,186 J/ gºC ( Tfinal - 25ºC)

19200 J = 2093 J/ºC ( Tfinal - 25ºC)

19200 J = 2093 J/ºC .Tfinal - 52,325 J

19200 J + 52325 J = 2, 093 J/ºC .Tfinal

71525 J = 2093 J/ºC .Tfinal

71525 J /2093 ºC / J = Tfinal = 34,17ºC

8 0

3 years ago