The correct options are as follows:
1. A.
A synthesis reaction is a type of reaction in which two or more reactants combine together to form only one product. Synthesis reaction always release energy in form of light and heat, therefore, they are usually exothermic reactions. In the option given in A, nitrogen and nitrogen combine together to form ammonia; this is a synthesis reaction.
2. D
A radioactive half life refers to the amount of time it will take for half of an original radioactive isotope to decay.
In the question given above, the half life of the element is 1000. Thus, in 1000 years only half of the original amount will remain. In another 1000 years only 1/4 of the original amount will remain and in another 1000 years only 1/8 of the original amount will remain. Therefore, it will take 3 half lives before 1/8 of the original sample remain.<span />
Answer:
0.4
Explanation:
Given data:
Number of moles of SrCl₂ consumed = ?
Mass of ZnCl₂ produced = 54 g
Solution:
Chemical equation:
ZnSO₄ + SrCl₂ → SrSO₄ + ZnCl₂
Number of moles of ZnCl₂:
Number of moles = mass/ molar mass
Number of moles = 54 g/136.3 g/mol
Number of moles = 0.4 mol
Now we will compare the moles of ZnCl₂ with SrCl₂ from balance chemical equation.
ZnCl₂ : SrCl₂
1 : 1
0.4 : 0.4
Thus when 54 g of ZnCl₂ produced 0.4 moles of SrCl₂ react.
Answer: The author used the word "conversely" because the first statement he made is in CONTRAST to the second statement he made.
Explanation:
Matter is made up of atoms or molecules that are in constant motion. The motion of these tiny particles ( molecules) gives the object energy. The movement of these molecules depends on the state of matter which includes
--> GASEOUS STATE: Here, the particles are completely free to move and are always in motion.
--> LIQUID STATE: particles in this state slide by one another and are always in motion.
--> SOLID STATE: particles in this state are held tightly together but are always in motion.
Also, the molecules in motion are greatly affected by temperature changes. Increase in temperature will cause the particles in the liquid to move faster. Such is seen when soup is heated, the molecules travel faster than before. But the OPPOSITE is seen in an ice cube. This is because the ice cube is in solid state and of a lower temperature.
4.1 h = 14760 s
<span>t 1/2 = ln 2 / k </span>
<span>k = rate reaction = 4.97 x 10^-5 </span>
<span>ln 0.045 / 0.36 = - 4.97 x 10^-5 t </span>
<span>2.08 = 4.97 x 10^-5 t </span>
<span>t = 41839.9 s = 11 h 37 min 19 s</span>
