T=20 min
m₀=200 g
t=60 min

the mass of element through time t is:
m=m₀*2^(-t/T)

m=200*2^(-60/20)=25 g

25 grams of element will be left after 60 minutes

5 0

3 years ago

Read 2 more answers

When calculating specific heat, what does the variable 'Q'

mariarad [96]

The answer is AIM NOT POSTIVE

4 0

2 years ago

Read 2 more answers

Hydrogen peroxide can decompose to water and oxygen by the following reaction

mestny [16]

To begin calculating, there is one thing you need to remember : $1 mole of H2O2=34.0148 g$
Then we have $5.00g of H2O2=5/34.0148=0.146995$
As you know decomposition of 2moles now has prodused 196kj
So, q is made due $0.146995 moles of H2O2$ $=(-196/2)*0.146995=-14.40551Kj$
I'm sure it will help.

6 0

3 years ago

Can the excess reactant control the percentage yield

katrin2010 [14]

Explanation:

when one reactants is in excess, there will always be some left over. The other reactants becomes limiting factor and controls show much of each product is produced.while using excess percentage yields this is at the expense of atom economy.

6 0

3 years ago