Answer:
1) Endothermic.
2)
3)
Explanation:
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1) In this case, for these calorimetry problems, we can realize that since the temperature decreases the reaction is endothermic because it is absorbing heat from the solution, that is why the temperature goes from 22.00 °C to 16.0°C.
2) Now, for the total heat released by the reaction, we first need to assume that all of it is released by the solution since it is possible to assume that the calorimeter is perfectly isolated. In such a way, it is also valid to assume that the specific heat of the solution is 4.184 J/(g°C) as it is mostly water, therefore, the heat released by the reaction is:
3) Finally, since the enthalpy of reaction is calculated by dividing the heat released by the reaction over the moles of the solute, in this case NH4Cl, we proceed as follows:

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Answer:
The answer is: 11759 Hz
Explanation:
Given: Chemical shift: δ = 211.5 ppm, Spectrometer frequency = 556 MHz = 556 × 10⁶ Hz
In NMR spectroscopy, the chemical shift (δ), expressed in ppm, of a given nucleus is given by the equation:



<u>Therefore, the signal is at 11759 Hz from the TMS.</u>
Answer:
2 Cr(s) + 3 Fe(NO3)2(aq) = 3 Fe(s) + 2 Cr(NO3)3(aq)
Explanation:
I balanced this chemical equation so that both sides are equal, meaning that the mass of reactants is equal to mass of products.
The metric system is based on powers of 10 so it is much easier to convert units, often just by moving the decimal point.