Numerade

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Ankur S

Numerade educator

What is the resulting temperature when 31 g of water at 87°C is mixed with 16 g of water at 22°C?

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Susan Hallstrom

Numerade educator

Hydrazine (N2H4) is a liquid often used as rocket fuel. Upon combustion, it yields nitrogen gas and liquid water. If a 22.8 g sample of N2H4 evolves 1660.1 kJ of heat during combustion, calculate the molar enthalpy change for the combustion of hydrazine?

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Nicole Smina

Numerade educator

Which of the following statements is/are correct If the reaction occurs at constant volume, ΔU > ΔH | Indien ŉ reaksie plaasvind onder konstante volume, sal DU > DH If the reaction occurs at constant pressure, q = ΔU | Indien ŉ reaksie plaasvind onder konstante druk, sal q = DU If the reaction occurs at constant pressure, q = ΔH | Indien ŉ reaksie plaasvind onder konstante druk, sal q = DH If the reaction occurs at constant volume, w = ΔU | Indien ŉ reaksie plaasvind onder konstante volume, sal w = DU If the reaction occurs at constant pressure, w = ΔU | Indien ŉ reaksie plaasvind onder konstante druk, sal w = DU

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Chareen Guzman

Numerade educator

A substance contains C, H and S only. Combustion analysis of a 264.4 mg sample of this substance gives 677.6 mg CO2 and 79.20 mg H2O. What is the empirical formula of the substance?

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Chareen Guzman

Numerade educator

Heroin has the molecular formula C21H23NO5. What mass in g of CO2 will be produced from combustion analysis of a 38.74 mg sample of heroin?

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INSTANT ANSWER

COMBUSTION OF HEROIN

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David Collins

Numerade educator

Under certain conditions the reaction below will proceed at 28.2% yield of NO. How many grams of NH3 must be reacted with excess oxygen to yield 125 g of H2O? Please give your answer to the correct number of significant figures. 4 NH3(g) + 5 O2(g) → 4 NO(g) + 6 H2O(g)

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John Incabo

Numerade educator

Which of the following molecular formulas are also empirical formulas? C3H4SO C6H12O4 HP4O6 H2O2 C3H6O3

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Ronald Prasad

Numerade educator

Of the reactions below, which are decomposition reactions? C2H5OH + 3O2 → 2CO2 + 3H2O PbCO3 → PbO + CO2 NH4NO3 → N2O + 2H2O N2 + 3H2 → 2NH3 2Mg + O2 → 2MgO

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Sima Sarker

Numerade educator

What is the concentration of the nitrate ion (NO3¯) in a solution prepared by diluting 1.00 mL of a 0.236 M solution of iron(III) nitrate to a volume of 100.0 mL?

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