Answer:
Explanation:
Q = Ce . m .ΔT
Q : calor  
Ce : calor especifico
m: masa  
ΔT : variación de temperatura
capacidad térmica : 0,550 cal / °C
lectura :
por 1 °C se tiene 0,550 cal
por lo tanto  tenemos datos de la temperatura y del calor
pero no olvidar las unidades en el sistema internacional :
Ce : J / kg . K
J: joules
kg: kilogramo
K: kelvin  
pasar de gramos a kilogramos
pasar de calorías a joules
pasar de grado celsius a kelvin
1000g equivale a 1kg
15g     equivale a 0,015 kg
K= °C + 273 ⇒ formula para pasar de grado celsius a kelvin
K=  1 + 273
K= 274
1 caloría equivale a  4,184 joules
0,550 caloría  equivale a 2,3012 joules
ahora como todos los datos ya están en el S.I remplazamos en la formula
Q = Ce . m .ΔT
2,3012 = Ce . 0,015.274
Ce=0,5599 J / kg. K
 
        
             
        
        
        
The amount of heat required is 9.0 kJ.
<em>q = mC</em>Δ<em>T
</em>
Δ<em>T</em> = <em>T</em>_f – <em>T</em>_i = 65 °C – 32 °C = 33 °C
<em>q</em> = 65 g × 4.184 J·°C⁻¹g⁻¹ × 33 °C = 9000 J = 9.0 kJ
 
        
                    
             
        
        
        
<h2>Let us complete it :</h2>
Explanation:
let us study about formation of sodium phosphide 
Electrons are transferred from atoms of  sodium to atoms of phosphorous 
The sodium atom looses electrons and the phosphorus atoms  
gains electrons .
C. This transfer makes the sodium atoms  acquire positive charge and phosphorous acquire negative charge .
As a result, the sodium and phosphorus atoms strongly  bond with 
each other.
 
        
        
        
They gain energy , it also allows plants to create organic molecules that they use as fuel. 
 
        
                    
             
        
        
        
D) if stuff is changing then the reaction is hardly in equilibrium is it? Everything is just chilling at equilibrium so there would be constant concentration