Answer:
The mass of the reactants compared with the mass of the products should be the same if the reactants are in stoichiometric amounts.
Explanation:
In this question, they ask about chemical reactions and the comparison of the mass of reactants and products. Firstly, it is necessary to introduce the mass conservation principle.
Mass conservation principle mentions that in a chemical reaction, the total mass of reactants is equal to the total mass of products (if the reaction is fully developed). It means mass is not created or destroyed, only transforms from reactants to products.
For example, the mass of sodium plus the mass of chlorine that reactswith the sodium equals the mass of the product sodium chloride.Because atoms are only rearranged in a chemical reaction, there mustbe the same number of sodium atoms and chlorine atoms in both thereactants and products.
Finally, we can conclude that The mass of the reactants compared with the mass of the products should be the same if the reactants are in stoichiometric amounts.
Answer:
- <u>Dependent variable</u>
Explanation:
In a controlled <em>experiment </em>there will be one independent variable, one dependent variable, and some controlled or constant parameters.
The target of the expermiment is to tes how the dependent variable changes with the independent variable.
So, the scientist will change (manipulate) the independent variable and measure the dependent vabiales.
Here, the temperature will be manipulated (within a range), so this is the independent variable; the height of the cake is the variable whose behavior wants to be determined, so this is the dependent variable. Controlled variables or constants may include the mixture, the size of the pan, the time of cooking, the oven, among others.
Answer:
d) cut the large sized Cu solid into smaller sized pieces
Explanation:
The aim of the question is to select the right condition for that would increases the rate of the reaction.
a) use a large sized piece of the solid Cu
This option is wrong. Reducing the surface area decreases the reaction rate.
b) lower the initial temperature below 25 °C for the liquid reactant, HNO3
Hugher temperatures leads to faster reactions hence this option is wrong.
c) use a 0.5 M HNO3 instead of 2.0 M HNO3
Higher concentration leads to increased rate of reaction. Hence this option is wrong.
d) cut the large sized Cu solid into smaller sized pieces
This leads to an increased surface area of the reactants, which leads to an increased rate of the reaction. This is the correct option.
Answer:
In a steam engine into a reciprocating piston cylinder assembly a high pressure steam is been admitted.
Explanation:
Steam engine: High-pressure steam is been injected into a piston-cylinder assembly which is reciprocating in nature. some part of its thermal energy gets converted into movement of the piston to work,When the steam starts expanding to lower pressure.
Apparatus which is separate and a condenser at comparatively low temperature and pressure here steam is passed.The expanded steam can then be made to be free, or, for engine efficiency to be maximum, Rotary motion with a crank-crankshaft assembly similar to that used in automobiles gets transferred from that.
Remaining heat has been now used for warming water.
boiler fired with coal, oil, or natural gas by them the steam gets supplied.
. In many areas, more reliable and economical diesel-electric locomotives gets supplanted by the steam locomotives.
The steam engines today generally are regarded as a unique piece as they are not considered as above reasons are explained.
Nevertheless, the creation of the steam engine played a vital role in the Revolution carried out by the industries by creating a society which now is less dependent on the different windmills, the watermills and mostly the animal power.
Answer:0.61L
Explanation:
P1V1/n1T1=P2V2/n2T2
n1=n2 T1=T2
Therefore;
P1V1=P2V2
225×1.4=515×V2
V2=0.61L
N.B: Increase in pressure leads to decreases in volume (Boyle's law)
