How many atoms are in 45.6 grams of sulfur

The isotope 208Tl undergoes Î² decay with a half-life of 3.1 min.

melamori03 [73]

Answer:

a. Pb 208

b. About 21.7 minutes

c. only a trace amount

Explanation:

It under goes beta decay.

There should be virtually nothing after an hour

8 0

3 years ago

Stearic acid (C18H36O2) is a fatty acid, a molecule with a long hydrocarbon chain and an organic acid group (COOH) at the end. I

Paha777 [63]

Answer:

There is 9671 Kj of heat released

Explanation:

Step 1: The balanced equation:

C18H36O2(s) + 26O2(g) --> 18CO2(g)+18H2O(g)

This means for 1 mole of C18H36O2 consumed there is 26 moles of O2 needed to produce 18 moles of CO2 and 18 moles of H2O.

Step 2: Calculate the heat of combustion

ΔH (combustion) = [18*(ΔHf of CO2) + 18*(ΔHf of H2O)] - [1*(ΔHf of C18H36O2) + 26*(ΔHf of O2)]

ΔH (combustion) = [18*(-394 kJ/mol) + 18*(-242 kJ/mol)] - [1*(-948 kJ/mol) + 26*(0 kJ/mol)]

ΔH (combustion) = [(-7092 kJ/mol) + (-4356 kJ/mol)] - (-948 kJ/mol)

= -10500 kJ/mol

ΔH (combustion) = heat released / number of moles of stearic acid

Step 3: Calculate moles of stearic acid

moles of stearic acid = mass / Molar mass of stearic acid

moles of stearic acid = 262g / 284.48 g/mole = 0.921 moles

Step 4: Calculate moles of oxygen

moles of O2 = 914.5 / 32g/mole

moles of O2 = 28.578125 moles

Stearic acid is the limiting reactant: it will completely react

There will react 26*0.921 mole = 23.946 mole of O2

This means there will remain 4.63 moles of O2

Step 5: Calculate heat released

q = (ΔH combustion) * (moles of stearic acid) = (-10500 kJ/mol) * (0.921 moles) = 9671 Kj

There is 9671 Kj of heat released

6 0

3 years ago

At 1 atm, how much energy is required to heat 75.0 g H 2 O ( s ) at − 20.0 ∘ C to H 2 O ( g ) at 119.0 ∘ C?

Hitman42 [59]

Answer:

238,485 Joules

Explanation:

The amount of energy required is a summation of heat of fusion, capacity and vaporization.

Q = mLf + mC∆T + mLv = m(Lf + C∆T + Lv)

m (mass of water) = 75 g

Lf (specific latent heat of fusion of water) = 336 J/g

C (specific heat capacity of water) = 4.2 J/g°C

∆T = T2 - T1 = 119 - (-20) = 119+20 = 139°C

Lv (specific latent heat of vaporization of water) = 2,260 J/g

Q = 75(336 + 4.2×139 + 2260) = 75(336 + 583.8 + 2260) = 75(3179.8) = 238,485 J

3 0

3 years ago

The Development and Characterization of Carbon Nanofiber/Polylactic Acid Filament for Additively Manufactured Piezoresistive Sen

horrorfan [7]

Compared to carbon nanotube, carbon nanofiber (CNF) is a unique quasi-one-dimensional nanostructure with a lot of edges and flaws (CNT). Additionally, their low cost and wide availability make them a valuable nanomaterial for upcoming technology.

<h3>what are the development and characterization of Carbon Nanofiber for Additively Manufactured Piezo resistive Sensors?</h3>

In accordance with the semiconductor material's piezo resistive effect, diffusion resistance is used to manufacture piezo resistive sensors on substrates of semiconductor materials. The diffusion resistor is connected in the substrate in the form of a bridge, allowing the substrate to be employed directly as a measuring sensor element.

Carbon nanofiber/polylactic acid filament for fused filament fabrication (FFF) and additive manufacturing (AM) strain sensors was studied for the effects of production factors.
To investigate the effects of CNF weight fraction, extrusion temperature, and number of extrusions on sensor performance, a design of experiments (DOE) approach was used. In the initial extrusion, dry melt mixing was used to combine CNFs and powdered PLA material.
Through the DOE procedure, it was discovered that extruding CNF/PLA material for two complete extrusions at 185 °C resulted in material with material with material with dramatically improved electrical characteristics in comparison to unmodified material.
Piezoresistive dog-bone shaped sensors were made using the best manufacturing technique using three different sizes of 5.0, 7.5, and 10.0 wt% CNF/PLA filament.

To know more about Carbon nanofiber/polylactic acid check here:brainly.com/question/15913091

#SPJ4

5 0

1 year ago

Where did water become gas?

ASHA 777 [7]

Answer: Water becomes gas at D-E.

Explanation:
In the flat line D-E water is absorbing energy to become gas, and when the water is completely gas, the temperature will increase again therefore the line will rise up.

8 0

3 years ago