Answer:
The temperature of the reaction mixture increases.
Explanation:
One very good indicator that a chemical reaction has taken place is that there is a temperature change about the reaction.
Either an emission of heat involving the reaction milieu becoming hotter or an absorption of heat making the environment colder.
- Enthalpy changes of reactions are good parameters to measure whether or not a reaction has taken place.
- There is no color change, and mass is always conserved for most reaction, so we cannot use these tools for assessing whether a reaction has occurred or not.
Answer:
No, cutting paper is a physical change. Meaning that it is still paper no matter how many times you cut it. its chemical properties have not changed and it is still paper. cutting it would just give you smaller pieces of paper.
Answer:
42.65g
Explanation:
Given parameters:
Mass of K = 4g
Unknown: Mass of KCl
Solution:
Complete equation of the reaction:
2K + Cl₂ → 2KCl
To solve this problem, we know that the reactant in short supply is potassium K and this dictates the amount of products that would be formed. The chlorine gas is in excess and we can't use it to determine the amount of product that would form.
Now, we work from the known to the unknown. Since we know the mass of K given in the reaction, we can simply find the molar relationship between the reacting potassium and the product. We simply convert the mass to mole and compare to the product. From there we can find the mass of KCl that would be produced.
Calculating number of moles of K
Number of moles = 
Number of moles of K = 
= 0.103mol
From the given reaction equation:
2 moles of K will produce 2 moles of KCl
Therefore 0.103mol of K will produce 0.103mol of KCl
To find the mass of KCl produced,
Mass of KCl = number of moles of KCl x molar mass
Molar mass of KCl = 39 + 35.5 = 74.5gmol⁻¹
Mass of KCl = 0.103 x 74.5 = 42.65g
Answer:
ER is present in both plants & animals
vacuole is present in plants only
Explanation:
Hope this helps :)
Answer: Mantle and core are the two layers of the earth that have convection currents.
Explanation:
The mantle and outer core are the two layers that are associated with the convection currents. In the mantle the convection currents occur due to the heat emerging out of the core also mantle region releases heat. If the transfer of heat or convection currents stop then the mantle will not flow and the core will not produce magnetic field at all. This will lead to coldness in earth and earth will lose the protection from harmful radiations.
