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2 years ago

HELP ME PLEASE PLEASE PLEASE IM TAKING A TIMED TEST

Chemistry

2 answers:

cricket20 [7]2 years ago

4 0

Answer: oxygen

Explanation: trust me bro

iragen [17]2 years ago

3 0

Answer: I think it is silver

Explanation:

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What is the density of ice at -10°C?

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3.98 C my friend you welcome

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3 years ago

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Suppose 550.mmol of electrons must be transported from one side of an electrochemical cell to another in 49.0 minutes. Calculate

nekit [7.7K]

Answer:

18.0 Ampere is the size of electric current that must flow.

Explanation:

Moles of electron , n = 550 mmol = 0.550 mol

1 mmol = 0.001 mol

Number of electrons = N

$N=N_A\times n$

Charge on N electrons : Q

$Q = N\times 1.602\times 10^{-19} C$

Duration of time charge allowed to pass = T = 49.0 min = 49.0 × 60 seconds

1 min = 60 seconds

Size of current : I

$I=\frac{Q}{T}=\frac{N\times 1.602\times 10^{-19} C}{49.0\times 60 seconds}$

$=\frac{n\times N_A\times 1.602\times 10^{-19} C}{49.0\times 60 seconds}$

$I=\frac{0.550 mol\times 6.022\times 10^{23} mol^{-1}\times 1.602\times 10^{-19} C}{49.0\times 60 seconds}=18.047 A\approx 18.0 A$

18.0 Ampere is the size of electric current that must flow.

3 0

3 years ago

A tank of gas has partial pressures of nitrogen and oxygen equal to 1.61 Ã— 104 kPa and 4.34 Ã— 103 kPa , respectively.What is t

Alchen [17]

Answer:

$20.44\times 10^3 kPa$ is the total pressure of the tank.

Explanation:

Partial pressures of nitrogen = $p_{N_2}=1.61\times 10^4 kPa$

Partial pressure of oxygen = $p_{O_2}=4.34\times 10^3 kPa$

Total pressure of gases in the tank = P

Applying Dalton's law of partial pressures :

$P=p_{N_2}+p_{O_2}=1.61\times 10^4 kPa+4.34\times 10^3 kPa$

$P=20.44\times 10^3 kPa$

$20.44\times 10^3 kPa$ is the total pressure of the tank.

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2 years ago

Calcium oxide and oxygen gas are produced by the thermal decomposition of limestone in the reaction CaCO (s) CaO(s) + CO (g). Wh

kozerog [31]

The mass of lime that can be produced from 4.510 Kg of limestone is calculated as below

calculate the moles of CaCO3 used

that is moles =mass/molar mass
convert Kg to g = 4.510 x1000 =4510g
= 4510 / 100 =45.10 moles
CaCO3 = CaO +O2

by use of mole ratio between CaCO3 to CaO (1:1) the moles of CaO is also= 45.10 moles
mass of CaO = moles x molar mass

45.10 x56 = 2525.6 g of CaO

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3 years ago

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