[.. مـَـحـبـّـة ..]

السلام عليكم
دكتورة عندي سؤالين ^_^
1 )
A piece of l with mass of 114 g was placed into a graduated cylinder contained 25 mL of water , raising the water level to 42.5 mL , what is the density ?
لما أحسب الكثافة بالقانون : الكتلة / الحجم
الكتلة عندي معطاة
بس الحجم آخذ النهائي و الا أطرح النهائي من الأول ؟؟


2 ) Which of the following statements is correct for the equation shown here :
4NH3 + 5O2 = 4NO + 6H2O

A-6 g of h2o are produced for every 4 g of NH3 reacted
b- one mole of NO is produced per mole of NH3 reacted
c- 2 moles of NO are produced for every 3 moles of O2 reacted

و جزاك الله خيراً على مجهوداتك :)