An air-standard Otto cycle has a compression ratio of 9. At the beginning of compression, p1 = 95 kPa and T1 = 310 K. The mass of air is 3 g, and the maximum temperature in the cycle is 1020 K. Determine:
(a). the heat rejection, in kJ,
(b). the net work, in kJ,
(c). the thermal efficiency,
(d). the mean effective pressure, in kPa.

The correct answer is b

The answer to this question is a

    pb(so₄)₂this element is lead (iv) sulfate. lead is a multivalent ion. but we know that sulfate ions, so₄²⁻, have a charge of -2. in order to have the ratios match up, we need pb⁴⁺ (two times as many pb⁴⁺  than so₄²⁻).the molar mass can be calculated by finding the mass of one mole of this compound. consider the following calculation,  where amu represents the atomic mass unit. the amu for each atom involved in this compound can be found on a periodic table.  molar mass = amu pb + 2(amu s + 4 * amu o)from a periodic table (with masses rounded to the nearest tenth),      amu pb = 207.2 g    amu s =  32.1 g    amu o = 16.0 gtherefore    molar mass =  207.2 + 2(32.1 + 4*16.0) = 399.4 gthe molar mass is therefore 399.4 grams per mol