Answer : The correct option is, (2) Cr (Chromium)
Explanation :
The reactivity series of metal are arranged of the reactivity from the highest to the lowest. Reactivity series is used to determine the products of the single displacement reactions. In the single displacement reaction, the most reactive metal displaces the least reactive metal.
From the given reactivity series we conclude that there are two metal (Mg and Cr) are more reactive metal than the Ni and there are two metal (Pb and Cr) are less reactive metal than the Zn. So, the Cr (Chromium) is the metal which is more active than Ni and less active than Zn.
Hence, the correct option is, (2) Cr
Answer:
pH = 2.462.
Explanation:
Hello there!
In this case, according to the reaction between nitrous acid and potassium hydroxide:
It is possible to compute the moles of each reactant given their concentrations and volumes:
Thus, the resulting moles of nitrous acid after the reaction are:
So the resulting concentration considering the final volume (20.00mL+13.27mL) is:
![[HNO_2]=\frac{6.73x10^{-4}mol}{0.01327L+0.02000L} =0.02023M](https://tex.z-dn.net/?f=%5BHNO_2%5D%3D%5Cfrac%7B6.73x10%5E%7B-4%7Dmol%7D%7B0.01327L%2B0.02000L%7D%20%3D0.02023M)
In such a way, we can write the ionization of this weak acid to obtain:
So we can set up its equilibrium expression to obtain x as the concentration of H3O+:
![Ka=\frac{[NO_2^-][H_3O^+]}{[HNO_2]}\\\\7.1x10^{-4}=\frac{x^2}{0.02023M-x}](https://tex.z-dn.net/?f=Ka%3D%5Cfrac%7B%5BNO_2%5E-%5D%5BH_3O%5E%2B%5D%7D%7B%5BHNO_2%5D%7D%5C%5C%5C%5C7.1x10%5E%7B-4%7D%3D%5Cfrac%7Bx%5E2%7D%7B0.02023M-x%7D)
Next, by solving for the two roots of x, we get:
Whereas the correct value is 0.003451 M. Finally, we compute the resulting pH:
Best regards!
Answer:
Risky behavior or risk-taking behavior is defined according to Trimpop (1994) as “any consciously, or non-consciously controlled behavior with a perceived uncertainty about its outcome, and/or about its possible benefits, or costs for the physical, economic or psycho-social well-being of oneself or others.” In addition to this broad definition, there are other definitions of risky behavior depending on the field of research. While in the economic view, risk is defined in terms of the variability of possible monetary outcomes, in the clinical literature, the risk is generally defined as exposure to possible loss or harm (Schonberg, Fox, & Poldrack, 2011). Turner et al. (2004) described risk-taking behavior further as either a socially unacceptable volitional behavior with a potentially negative outcome in which precautions are not taken, such as speeding, drinking and driving, drugs abuse, unprotected sex and so on.
Answer:
Its because the steam promotes rust
Explanation:
Water vapour tends to oxidise iron...hence promoting rust
