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yawa3891 [41]
1 year ago
14

Select only one most suitable description

Chemistry
1 answer:
Annette [7]1 year ago
3 0
I believe it's a pure element
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Calculate the number of moles in 2.67 g of carbon trihydride
Scorpion4ik [409]

Answer:0.178 moles

Explanation: carbon trihydride seems to be an unusual name for the methyl group CH3–

ionic wt 15

moles = 2.67/15 = 0.178

8 0
2 years ago
A catalyst is:<br> one answer only pls help lol
natka813 [3]
A catalyst is a substance that speeds up a chemical reaction.
3 0
3 years ago
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What is the sign of enthalpy change for (a), an endothermic reaction? (b). an exothermic reaction?
fenix001 [56]

Answer:

The answer is: (a) positive; (b) negative.

Explanation:

The change in enthalpy (ΔH) of a reaction is the amount of energy absorbed or released during a chemical reaction carried out at constant pressure.

a) In an endothermic chemical reaction, heat energy is absorbed by the system from the surrounding. Therefore, the sign of enthalpy change for an endothermic process is positive, ΔH= positive.

b) In an exothermic chemical reaction, heat energy is released by the system into the surrounding. Therefore, the sign of enthalpy change for an exothermic process is negative, ΔH= negative.

8 0
3 years ago
If a gas has a molecular mass of 44.0, the volume of 88.0 grams of the gas at STP would be ..
Montano1993 [528]
2) 11.2
All you have to do is multiply 44 by 22.4 L, which equals 985.6
Then you divide 985.6 by 88 to get your answer of 11.2 L
3 0
2 years ago
Many portable gas heaters and grills use propane, C3H8(g). Using enthalpies of formation, calculate the quantity of heat produce
Elodia [21]

Answer:  600 kJ

-

Explanation:

                        C₃H₈ (g)  + 5 O₂ (g) =============== 3 CO₂ (g)  +  4 H₂O (l)

Δ⁰Hf   kJ/mol       -104             0                                       -393.5         -285.8

Δ⁰Hcomb C₃H₈ = 3(-393.5) + 4 (-285.80) - (-104)  kJ/mol

Δ⁰Hcomb = 2219.70 kJ/mol

n= m /MW   MW c₃H₈ = 44.1 g/mol

n= 12 g/44.1 g/mol = 0.27 mol

then for 12 g the heat released will be

0.27 mol x 2219.70 kJ/mol =  600 KJ

4 0
2 years ago
Read 2 more answers
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