The number of grams of Mgo that are produced is calculated as follows
calculate the moles of Mg used
that is moles =mass/molar mass
= 3.45 g/ 24.305g/mol = 0.142 moles
write the equation for reaction
that is 2 Mg + O2 = 2 MgO
by use of mole ratio between Mg to Mgo which is 2:2 this implies that the moles of Mgo is also 0.142 moles
mass of Mgo= moles x molar mass of MgO
molar mass of Mgo = 24.305 + ( 3x15.999) = 72.302 g/mol
mass= 0.142 mol x 72.302 g/mol= 10.27 grams
Answer:
Mass is the amount of matter in the object, and is not affected by gravity. Weight, on the other hand, is directly related to gravity and how much you pull to the ground.
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correct answer is C) Identifying areas of rain and identifying speeding
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Radars used in predicting rain and
measuring speed make use of the Doppler effect. Waves from the radar bounce
from an object and get reflected back to the source.
Answer:
D. -120.9 kJ
Explanation:
According to Hess's law ,the total enthalpy change for a reaction is the sum of all changes regardless of the stages or the steps of the reaction.
....(1)
(this reaction should be reversed in order to reach the required reaction )
On reversing the reaction the sign of 
get reversed.
(In this case change sign from '-' to'+'. Hence = + 65 kJ)
....(1)
......(2)
Adding equation (1) and (2)
![Ca(OH)_{2} + 2HCl \rightarrow CaCl_{2} + 2H_{2}O[tex][tex]Delta H = - 186 + 65 = - 121\kJ](https://tex.z-dn.net/?f=%3Cstrong%3ECa%28OH%29_%7B2%7D%20%2B%202HCl%20%5Crightarrow%20CaCl_%7B2%7D%20%2B%202H_%7B2%7DO%3C%2Fstrong%3E%5Btex%5D%3C%2Fp%3E%3Cp%3E%5Btex%5D%3Cstrong%3EDelta%20H%20%3D%20-%20186%20%2B%2065%20%3D%20-%20121%5CkJ%3C%2Fstrong%3E)
(It is nearly equal to -120.9 kJ)
Answer:
EIt involves copying a gene's DNA sequence to make an RNA molecule. Transcription is performed by enzymes called RNA polymerases, which link nucleotides to form an RNA strand (using a DNA strand as a template). ... Transcription is controlled separately for each gene in your genome.xplanation:
