بليز ساعدوني في حل مساىل للكيمياء

[الثنائي المرح]

[2] A flask of nitrogen is collected over water at a total pressure of 740 mmHg. If the partial pressure of the water vapor is 15 mmHg, what is the pressure exerted by the nitrogen?
الجواب
(A) 725 mmHg

مو اجمع بس ليش يطلع كداء

A sample of gas weighs 0.250 g and occupies a volume of 112 cm3 at STP. The molecular weight of this gas is:

(A) 50 g mol-1

In the reaction 2Na + 2H2O ➜ 2NaOH + H2 , how many liters of hydrogen at STP are produced from 70.0 grams of sodium?

(A) 34.1 L