8. Well-aerated soils have the ______________

A piece of unknown metal with mass 68.6 g is heated to an initial temperature of 100 °C and dropped into 42 g of water (with an

professor190 [17]

Answer:

1.717 J/g °C ( third option)

Explanation:

A piece of the unknown metal dropped into water this means that Q of metal is equal to Q of the water. We write this equality as follows:

Step 1: writing the formulas:

Q = mc∆T

⇒ -Q(metal) = Q(water) Because :Metal dropped into water this means that Q of metal is equal to Q of the water.

We can write the formula different :

Mass of metal * (cmetal)(ΔT) = Mass of water *(cwater) (ΔT)

⇒ Here c is the specific heat and depends on material and phase

For this case :

mass of the metal = 68.6g

mass of the water = 42g

Specific heat of the metal = TO BE DETERMINED

Specific heat of the water = 4.184J/g °C

Initial temperature of the metal = 100 °C ⇒ Change of temperature: 52.1 - 100

Initial temperature of the water = 20°C ⇒ Change of temperature: 52.1 - 20

Step 2: Calculating specific heat of the metal

-(Mass of metal) * (cmetal)*(ΔT)) = (Mass of water) *(cwater)*(ΔT)

-68.6g (cmetal)(52.1 - 100) = 42g (4.184j/g °C) (52.1 - 20)

-68.6g *cmetal * (-47.9) = 42g (4.184j/g °C) *(32.1)

3285.94 * cmetal = 5640.87

cmetal = 5640.87 / 3285.94 = 1,71667 J/g °C

cMetal = 1.717 J/g °C

4 0

3 years ago

Pure magnesium metal is often found as ribbons and can easily burn in the presence of oxygen. When 3.97 g of magnesium ribbon bu

taurus [48]

Answer:

The balanced chemical equation is given as:

$2Mg(s)+O_2(g)\rightarrow 2MgO(s)$

Explanation:

When magnesium metal burns in presence of oxygen it gives white color powdered compound called magnesium oxide.

The balanced chemical equation is given as:

$2Mg(s)+O_2(g)\rightarrow 2MgO(s)$

According to reaction, 2 moles of magnesium metal when reacts with 1 mole of oxygen gas it gives 2 moles of solid magnesium oxide.

3 0

3 years ago

How many hours will it take for the concentration of methyl isonitrile to drop to 15.0 % of its initial value?

SpyIntel [72]

Answer:

The concentration of methyl isonitrile will become 15% of the initial value after 10.31 hrs.

Explanation:

As the data the rate constant is not given in this description, However from observing the complete question the rate constant is given as a rate constant of 5.11x10-5s-1 at 472k .

Now the ratio of two concentrations is given as

$ln (\frac{C}{C_0})=-kt$

Here C/C_0 is the ratio of concentration which is given as 15% or 0.15.

k is the rate constant which is given as $5.11 \times 10^{-5} \, s^{-1}$

So time t is given as

$ln (\frac{C}{C_0})=-kt\\ln(0.15)=-5.11 \times 10^{-5} \times t\\t=\frac{ln(0.15)}{-5.11 \times 10^{-5} }\\t=37125.6 s\\t=37125.6/3600 \\t= 10.31 \, hrs$

So the concentration will become 15% of the initial value after 10.31 hrs.

7 0

3 years ago

Read 2 more answers

Decide which element probably has a boiling point most and least similar to the boiling point of cesium.

natka813 [3]

Answer:

Take a look at the attachment below

Explanation:

Take a look at the periodic table. As you can see, Rubidium is the closest element to Cesium, and happens to have the closest boiling point to Cesium, with only a difference of about 30 degrees.

Respectively, you would think that fluorine should have the least similarity to Cesium with respect to it's boiling point, considering it is the farthest away from the element out of the 4 given. This is not an actual rule, there are no fixed trends of boiling points in the periodic table, there are some but overall the trends vary. However in this case fluorine does have the least similarity to Cesium with respect to it's boiling point, a difference of about 1,546.6 degrees.

Hope that helps!

5 0

3 years ago

The law of constant composition states: All atoms of a given element have a constant composition and are different than atoms of

Airida [17]

Answer:

C

Explanation:

The law proves C. For examples no matter how water you have it will always have a 1:2 ratio of oxygen to hydrogen. :)

7 0

2 years ago

8. Well-aerated soils have the _______________ smell of good soil.