27.7 21. In the Haber process: \( \mathrm{N} z(\mathrm{~g})+3 \mathrm{H}_{2}(\mathrm{~g}) \rightleftharpoons 2 \mathrm{NH}_{3}(\mathrm{~g}) \quad \Delta H=-92 \mathrm{~kJ} \mathrm{~mol}^{-1} \) Explain the following conditions used: (a) Nitrogen is added in excess; (b) The process is not carried out at very high temperature; (c) The process is not carried out at very low temperature; (d) A suitable catalyst is used; (e) The process is carried out at high pressure; (f) Ammonia is liquefied and be removed continuously.

3. En qué época tomó relevancia la estadistica eng fútbol:

\( \left. \begin{array} { c } { A = \{ \frac { 1 } { 3 } , \frac { 5 } { 4 } , \frac { 11 } { 2 } , \frac { 7 } { 8 } , \frac { 25 } { 3 } \} } \\ { B = \{ \frac { 1 } { 4 } , \frac { 35 } { 40 } , \frac { 15 } { 12 } , \frac { 11 } { 3 } , \frac { 25 } { 4 } \} } \\ { C = \{ x \in Q | x < 1 \} } \\ { D = \{ x \in Q | x > 2 \} } \end{array} \right. \)

What is the value of the expression \( m^{2}+n^{3} \) \( 2 n m \) for \( m=4 \) and \( n=-5 \) ?

Given \( f(x)=2 x^{3}-9 x^{2}+1 \), which of the following is correct? \( f \) has local maximum at \( x=3 \) \( f(x)<0 \) on \( (-\infty, 0) \) \( f \) has local maximum at \( x=0 \) \( f(x)>0 \) on \( (-\infty, 0) \)

Her work is shown below. \( -15 \frac{1}{2}+5 \frac{3}{4} \) \( =-\frac{31}{2}+\frac{23}{4} \) \( =-\frac{31}{2} \times \frac{23}{4} \) \( =-\frac{713}{8} \) When she checked the answer by estimating, it did not make sense. What error did Wen make? Wen incorrectly converted a mixed number to an improper fraction. Wen added the numerators and denominators instead of multiplying. Wen did not take the reciprocal of the divisor. We the division problem to multiplication.