If an electron is released during radioactive decay which type of Decay has taken place

When hydrochloric acid is poured over potassium sulfide, 43.7 mLmL of hydrogen sulfide gas is produced at a pressure of 758 torr

kvasek [131]

Answer:

0.196 grams of K2S reacted

Explanation:

When hydrochloric acid is poured over potassium sulfide, 43.7 mLmL of hydrogen sulfide gas is produced at a pressure of 758 torrtorr and 26.0 ∘C

How much potassium sulfide has reacted in grams?

Step 1: Data given

Volume of hydrogen sulfide (H2S) produced = 43.7 mL

Pressure = 758 torr = 758/760 = 0.9973684 atm

Temperature = 26.0 °C = 273 + 26 = 299 K

Step 2: The balanced equation

2 HCl + K2S → H2S + 2 KCl

Step 3: Calculate moles H2S

p*V = nRT

n = (pV)/(RT)

⇒ with n= the number of moles of H2S

⇒ with p = the pressure = 0.9973684 atm

⇒ with V = the volume of the gas = 43.7 mL = 0.0437 L

⇒ with R = the gas constant = 0.08206 L*atm/K*mol

⇒ with T = The temperature = 26°C = 299 Kelvin

n = (0.9973684 * 0.0437)/ (0.08206*299)

n = 0.001776 moles H2S

Step 4: calculate moles of K2S

For 2 moles HCl we need 1 mol K2S to produce 1 mol H2S and 2 moles KCl

For 0.001776 moles H2S produced, we need 0.001776 moles K2S

Step 5: Calculate mass of K2S

Mass K2S = moles K2S * molar mass K2S

Mass K2S = 0.001776 moles * 110.26 g/mol

Mass K2S = 0.196 grams K2S

0.196 grams of K2S reacted

6 0

3 years ago

A 100 g sample of an unknown liquid absorbs 2000 j of heat energy, raising the liquid's temperature from 50 ◦ c to 70 ◦

Mekhanik [1.2K]

Since there is no phase change, we can use the heat equation,
Q = mcΔT
where Q is the amount of energy transferred (J), m is the mass of the substance (kg), c is the specific heat (J kg⁻¹ °C⁻¹) and ΔT is the temperature difference (°C).

Q = 2000 J
m = 100 g = 0.1 kg
c = ?
ΔT = (70 °C - 50 °C) = 20 °C

By applying the formula,
2000 J = 0.1 kg x c x 20 °C
c = 2000 J / (0.1 kg x 20 °C)
c = 1000 J kg⁻¹ °C⁻¹

Hence, the specific heat capacity of the liquid is 1000 J kg⁻¹ °C⁻¹.

5 0

4 years ago

How long does it take for the water to start boiling? At what temperature does the water boil?

Wewaii [24]

Answer:

At sea level, or at zero feet in altitude, the boiling point of water is at 212 °F (100 °C). Once the water has reached this boiling point, the US Center for Disease Control recommends keeping it at a rolling boil for about a minute to make sure it is purified.

6 0

4 years ago

Read 2 more answers

Chromium metal can be produced by the following reaction:

Mrac [35]

Answer:

17.3 g Cr

Explanation:

To find the mass of chromium, you need to (1) convert moles Si to moles Cr (using the mole-to-mole ratio from equation coefficients) and then (2) convert moles Cr to grams Cr (using the atomic mass). It is important to arrange the conversions in a way that allows for the cancellation of units. The final answer should have 3 sig figs to match the sig figs of the given value (0.250).

3 Si + 2 Cr₂O₃ ---> 4 Cr + 3 SiO₂
^ ^

Atomic Mass (Cr): 51.996 g/mol

0.250 moles Si 4 moles Cr 51.996 g
------------------------- x -------------------- x ------------------- = 17.3 g Cr
3 moles Si 1 mole

6 0

2 years ago

A common fuel additive that is composed of C, H, and O enhanced the performance of gasoline began being phased out in 1999 becau

spayn [35]

Answer:

C₅ H₁₂ O

Explanation:

44 g of CO₂ contains 12 g of C

30.2 g of CO₂ will contain 12 x 30.2 / 44 = 8.236 g of C .

18 g of H₂O contains 2 g of hydrogen

14.8 g of H₂0 will contain 1.644 g of H .

total compound = 12.1 out of which 8.236 g is C and 1.644 g is H , rest will be O

gram of O = 2.22

moles of C, O, H in the given compound = 8.236 / 12 , 2.22 / 16 , 1.644 / 1

= .6863 , .13875 , 1.644

ratio of their moles = 4.946 : 1 : 11.84

rounding off to digits

ratio = 5 : 1 : 12

empirical formula = C₅ H₁₂ O

6 0

3 years ago