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3 years ago

Which species is the reducing agent in the reaction: 3ca (s) + 2cr3+ (aq) 2cr (s) + 3ca2+ (aq)?

1 answer:

3 0

The redox reaction is as follows
3Ca + 2Cr³⁺ --> 3Ca²⁺ + 2Cr
in the oxidation reaction the species donates electrons and becomes oxidised.
the oxidised species donates electrons to the other species and reduces the other species hence its called the reducing agent as it reduces the other species. the oxidised species' oxidation number increases.
in the reduction reaction, the species takes in electrons and becomes electrons and its called the oxidising agent as it takes in electrons from the oxidised species thus oxidising the other species. the reduced species' oxidation number decreases.

in this case , Ca becomes oxidised
Ca --> Ca²⁺ + 2e
oxidation number of Ca increases from 0 to +2. since it reduces Cr from Cr³⁺ to Cr, Ca is called the reducing agent

hence answer is Ca, its the reducing agent

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The main product of the photosynthesis reaction is

Paladinen [302]

Answer: Sugar

Explanation: Because after photosynthesis (Carbon dioxide, water, and sunlight) react, they make two products. Glucose (A sugar) and Oxygen.

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3 years ago

A 3.42 gram sample of an unknown gas is found to occupy a volume of 1.90 L at a pressure of 547 mm Hg and a temperature of 33 °C

liq [111]

Use the Ideal Gas Law to find the moles of gas first.

Be sure to convert T from Celsius to Kelvin by adding 273.

Also I prefer to deal with pressure in atm rather than mmHg, so divide the pressure by 760 to get it in atm.

PV = nRT —> n = PV/RT
P = 547 mmHg = 547/760 atm = 0.720 atm
V = 1.90 L
T = 33°C = 33 + 273 K = 306 K
R = 0.08206 L atm / mol K

n = (0.720 atm)(1.90 L) / (0.08206 L atm / mol K)(306 K) = 0.0545 mol of gas

Now divide grams by mol to get the molecular weight.

3.42 g / 0.0545 mol = 62.8 g/mol

3 0

3 years ago

What is 254 K in degrees Celsius. Show all work and include units for full credit.

kondor19780726 [428]

-19.15 degrees Celsius. 254k-273.15=-19.15
You have to subtract 273

6 0

3 years ago

What is the net ionic equation for the reaction if any that occurs when aqueous solutions of Na2CO3 and HCL are mixed?

strojnjashka [21]

Answer:

CO₃²⁻(aq) + 2H⁺(aq) → CO₂ (g) + H₂O (l)

Explanation:

The balanced reaction between Na2CO3 and HCl is given as;

Na₂CO₃ (aq) + 2 HCl (aq) → 2 NaCl (aq) + CO₂ (g) + H₂O (l)

The next step is o express the species as ions.

The complete ionic equation for the above reaction would be;

2Na⁺(aq) + CO₃²⁻(aq) + 2H⁺(aq) + 2Cl⁻(aq) → Na⁺(aq) + Cl⁻(aq) + CO₂ (g) + H₂O (l)

The next step is to cancel out the spectator ion ions; that is the ions that appear in both the reactant and product side unchanged.

The spectator ions are; Na⁺ and Cl⁻

The net ionic equation is given as;

CO₃²⁻(aq) + 2H⁺(aq) → CO₂ (g) + H₂O (l)

7 0

3 years ago

If the atmospheric pressure in the laboratory is 1.2 atm, how many moles of gas were in each syringe? (Hint: Choose one volume a

Naily [24]

Answer:

A: 2.525 x 10-4 mol

B: 2.583 x 10-4 mol

Explanation:

Part A:

Data Given:

. Temperature of water (H2O) = 21.3°C

Convert Temperature to Kelvin

T = °C + 273

T = 21.3 + 273 = 294.3 K

volume of (H2O) gaseous state = 5.1 mL

Convert mL to liter

1000 mL = 1L

5.1 ml = 5.1/1000 = 0.0051 L

Pressure = 1.2 atm

. no. of moles = ?

Solution

no. of moles can be calculated by using ideal gas formula

PV = nRT

Rearrange the equation for no. of moles

n=PV/RT......... (1)

where

P = pressure

V = Volume

T= Temperature

n = Number of moles

R = ideal gas constant

where

R = 0.08206 L.atm/ mol. K

Now put the value in formula (1) to calculate no. of moles of

n = 1.2 atm x 0.0051 L / 0.08206 L.atm.mol-1. K-1 x 294.3 K

n = 0.0061 atm.L / 24.162 L.atm.mol-1

n = 2.525 x 10-4 mol

no. of moles of gas (H2O) = 2.525 x 10-4 mol

Part B:

Data Given:

Temperature of water (H2) = 21.3°C

Convert Temperature to Kelvin

T = "C + 273

T= 21.3 + 273 = 294.3 K

volume of (H2) gas = 5.2 mL

Convert mL to liter

1000 mL = 1 L

5.2 ml = 5.2/1000 = 0.0052 L

Pressure = 1.2 atm

. no. of moles = ?

Solution

no. of moles can be calculated by using ideal gas formula

PV = nRT

Rearrange the equation for no. of moles

n= PV / RT......... (1)

where

P = pressure

V = Volume

T= Temperature

n = Number of moles

R = ideal gas constant

where

R = 0.08206 L.atm/mol. K

Now put the value in formula (1) to calculate no. of moles of

n = 1.2 atm x 0.0052 L/0.08206 L.atm.mol-1. K-1 x 294.3 K

n = 0.0062 atm.L/ 24.162 L.atm.mol-1

n = 2.583 x 10-4 mol

no. of moles of gas (H2) = 2.583 x 10-4 mol

8 0

3 years ago