Jaká je hmotnost uhličitanu sodného, který obsahuje právě 14 g sodíku? Ar(Na) = 23
Správná odpověď je: A
Molární hmotnost Na2CO3 je 106 g/mol. 1 mol Na2CO3 obsahuje 2 moly sodíku. Je tedy nutné vypočítané látkové množství sodíku vydělit dvěma. Výpočet provedeme následovně:
m(uhličitan) = {[m(Na)/M(Na)]/2} · M(uhličitan)
m(uhličitan) = [(14/23)/2] · 106 = 32,3 g.
Cookie | Délka | Popis |
---|---|---|
_fbp | 3 months | Facebook sets this cookie to display advertisements when either on Facebook or on a digital platform powered by Facebook advertising after visiting the website. |
_ga | 1 year 1 month 4 days | Google Analytics sets this cookie to calculate visitor, session and campaign data and track site usage for the site's analytics report. The cookie stores information anonymously and assigns a randomly generated number to recognise unique visitors. |
_ga_* | 1 year 1 month 4 days | Google Analytics sets this cookie to store and count page views. |
sbjs_current | session | Sourcebuster sets this cookie to identify the source of a visit and stores user action information in cookies. This analytical and behavioural cookie is used to enhance the visitor experience on the website. |
sbjs_current_add | session | Sourcebuster sets this cookie to identify the source of a visit and stores user action information in cookies. This analytical and behavioural cookie is used to enhance the visitor experience on the website. |
sbjs_first | session | Sourcebuster sets this cookie to identify the source of a visit and stores user action information in cookies. This analytical and behavioural cookie is used to enhance the visitor experience on the website. |
sbjs_first_add | session | Sourcebuster sets this cookie to identify the source of a visit and stores user action information in cookies. This analytical and behavioural cookie is used to enhance the visitor experience on the website. |
sbjs_migrations | session | Sourcebuster sets this cookie to identify the source of a visit and stores user action information in cookies. This analytical and behavioural cookie is used to enhance the visitor experience on the website. |
sbjs_session | 1 hour | Sourcebuster sets this cookie to identify the source of a visit and stores user action information in cookies. This analytical and behavioural cookie is used to enhance the visitor experience on the website. |
sbjs_udata | session | Sourcebuster sets this cookie to identify the source of a visit and stores user action information in cookies. This analytical and behavioural cookie is used to enhance the visitor experience on the website. |
Cookie | Délka | Popis |
---|---|---|
lp_session_guest | 2 days | Description is currently not available. |
uloha_switch | 1 day | Description is currently not available. |